The Development of Sweet Potato Washing Among the Japanese Macaques

The development of sweet potato washing among the Japanese macaques of Koshima Island is of interest to students of human evolution because:

A) the monkeys were observed using simple tools to help clean the sweet potatoes
B) the eating of sweet potatoes was not accepted by the troop until the adult males adopted it
C) a single monkey developed a new behavior,and this behavior was transmitted to the rest of the population
D) the monkeys developed new vocalizations to accompany the activity of sweet potato washing