After one chimpanzee sees a second chimp open a box that contains a food reward, the first animal opens a similar box with great speed.

This best illustrates:

a) shaping.

b) spontaneous recovery.

c) respondent behavior.

d) observational learning.

e) positive reinforcement.

The reaction of the second chimpanzee after he watches that the first one found food reward inside a box is called d) "observational learning"

Explanation:

Observational learning is a form of social learning in which a subject observed a result after another subject presented a singular behavior which granted him a reward the observing individual would like to get.

In humans, this type of learning happens with almost no direct reinforcement, but with a social indirect reward after watching someone the observing individual considers as a "model" performing the behavior to imitate it. It is a very common way children learn and how they start to interact with the world.