Question

crystal size tells us about how quickly the magma cooled. which is statement is true for large crystal growth
cooling speed does not affect crystal size
fast cooling
slow cooling

Explanation:

Step1: Analyze the graph

The graph shows a positive correlation between crystal size and time to cool.

Step2: Relate cooling speed to crystal size

Slow cooling (more time to cool) leads to larger crystals as per the graph. Fast cooling would lead to smaller crystals (less time to cool). And the graph clearly shows a relation so "Cooling speed does not affect crystal size" is wrong.

Answer:

Slow cooling