Question

which is the smallest division of geologic time?
a. period
b. era
c. eon
d. epoch

Explanation:

To determine the smallest division of geologic time, we analyze the hierarchical structure of geologic time units. From largest to smallest, the order is Eon, Era, Period, and then Epoch. So among the given options (Period, Era, Eon, Epoch), Epoch is the smallest.

Answer:

D. Epoch