user_prompt: ## Instruction:
  You enter a large hall. The entrance is located at the south end. The hall is long in the north-south direction but not very wide in the west-east direction.
  
  After entering and gazing into the hall, you see an elevated blue path stretching from the right wall to the left wall. Between the entrance and the middle part, there is a ditch filled with water. In the middle section of the hall, there is laser slot 1 on the right wall, and laser slot 2 is directly at the south wall, immediately to the left of the entrance.
  
  Laser slot 1 is connected to platform 1, and laser slot 2 is connected to platform 2. By default, platform 1 starts at mid-level, and platform 2 starts at high level. When a laser slot is activated, its respective platform lowers by one position (high to mid or mid to ground). When the laser slot is deactivated, the platform returns to its default position.
  
  At the west wall, there are two cube machines (circular structures on the ceiling) that have dropped a mirror cube each onto an elevated large platform that cannot be reached directly from the floor.
  
  Select the correct options for each blank. Only output option letters one by one, with the format '{Option 1}{Option 2}{Option 3}{Option 4}{Option 5}, such as 'ABCDE'
  Step 1: ________
  Step 2: Walk along the new blue path on ground level across the water ditch between the entrance and the center of the hall.
  Step 3: Shoot a blue portal where the laser source hits the wall. Shoot an orange portal at the southernmost white wall piece (ground level) on the west wall. Step onto platform 1.
  Step 4: ________
  Step 5: ________
  Step 6: Shoot a blue portal where the blue path hits the wall and an orange portal on the ground-level white wall piece at the north wall.
  Step 7: ________
  Step 8: Place the second mirror cube on the blue path further south than the first cube so that the laser is directed into laser slot 1 (e.g., pointing the laser toward the east wall).
  Step 9: ________
  Step 10: The second mirror cube falls down, activating laser slot 2. Step onto the second platform.
  Step 11: Shoot the orange portal onto a white wall section at a north-facing corner of the west wall, opposite the exit door.
  Step 12: After platform 2 elevates, jump onto the blue path and walk into the exit door. Problem solved.
  
  Please select from the following candidate choices. Your response should end with "The final answer is [answer]." where the [answer] is the choice of options. 
  A. Shoot the orange portal onto a random white wall section on the ceiling to deactivate laser slot 2, causing platform 2 to elevate again. Jump over to the large platform and throw both mirror cubes down.
  B. Walk onto platform 1. Shoot an orange portal on the white wall of the east wall directly behind the first cube so that the blue path extends from the east to the west wall and holds the first mirror cube.
  C. Shoot the orange portal onto the ground-level white wall piece at the north wall so that the second laser slot is activated. Step onto platform 2 at mid-level height.
  D. Walk onto platform 1. Shoot an orange portal on the white wall of the east wall directly behind the first cube so that the blue path extends from the east to the west wall, but the first mirror cube falls down.
  E. Shoot a blue portal on the ground-level white wall of the north side of the room. Shoot an orange portal on the white wall on the left (west wall) where the blue path hits the wall.
  F. Go to Room 2 via the portals so the shield wall does not destroy the connection between the rooms.
  G. Shoot a blue portal on the ground-level white wall of the south side of the room (left of the entrance). Shoot an orange portal on the white wall on the left (west wall) where the blue path hits the wall.
  H. Shoot the orange portal onto the ground-level white wall piece at the north wall so that the first laser slot is activated. Step onto platform 2 at mid-level height.
  I. Place the first mirror cube on the blue path where the path crosses the laser. Orient the cube so that it redirects the laser southward toward laser slot 2.
  J. Walk across the new bridge to the jumper and jump up to the exit.