Answer:
A. Smaller ice cubes have more surface area in contact with the liquid water, so more thermal energy is transferred from the water to the ice.
Explanation:
The surface area of the smaller ice cubs are more as compared to the block of ice. Hence, the surface area exposed to the outer environment is more. It is because of this reason that more thermal energy is transferred from water to ice cubs than the ice block. more heat was absorbed by the ice cubes. This helped the ice cubes to melt faster.