- As the rate of rocks cooling decreases , the crystal size of the rock will increase
- Rate is a kind of measurement of speed
- Hence, as the speed of rocks cooling decreases, the crystal size of the rock will increase

- "Sneezing is used for getting rid of bacteria / viruses by the body " is not a useful statement here

- As the speed of rocks cooling decreases, the crystal size of the rock will increase
- To slow / to slow down decreases speed
- So, a rock cooling slowly causes the crystal size of the rock to increase

- A rock cooling slowly causes the crystal size of the rock to increase
- If something causes something else then that something affects that something else
- So, a rock cooling slowly affects the crystal size of the rock

- A rock cooling slowly affects the crystal size of the rock
- If something affects something else then that something else indicates whether that something happened
- Hence, the crystal size of a rock indicates whether the rock cooled slowly

- The crystal size of a rock indicates whether the rock cooled slowly
- Crystal size is a property of rocks and includes values of small / large
- Hence, crystal size is a property of a rock that indicates whether a rock cooled slowly

Hence, crystal size is a property of a rock that indicates whether a rock cooled slowly
Question: Which characteristic property indicates that igneous rock cools slowly?
Context: - If something causes something else then that something affects that something else 
- Sneezing is used for getting rid of bacteria / viruses by the body 
- As the rate of rocks cooling decreases , the crystal size of the rock will increase 
- Crystal size is a property of rocks and includes values of small / large 
- Rate is a kind of measurement of speed 
- To slow / to slow down decreases speed 
- If something affects something else then that something else indicates whether that something happened