Final answer:
Type IV concrete is the correct answer as it is designed for mass concrete structures to minimize thermal effects and prevent cracking due to a lower heat of hydration.
Step-by-step explanation:
The type of concrete that has a low heat of hydration is Type IV concrete. It is specifically designed for mass concrete structures like large dams, where the thermal effect must be minimized to avoid cracking. Type IV concrete achieves slower and lower heat development during the curing process compared to other types of Portland cement. In contrast, Type III concrete is known for high early strength and higher heat of hydration, whereas Type I concrete is the most commonly used with a standard rate of heat development, and Type II concrete offers moderate resistance to sulfate attack with a moderate heat of hydration.