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.
  
  Below is a candidate solution:
  Step 1: 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.
  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: 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.
  Step 5: 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.
  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: 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.
  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: 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.
  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 choose from the following options. Your response should end with "The final answer is [answer]." where the [answer] is the choice of A or B.
  A. Correct
  B. InCorrect