A girl learns that whenever her brother shares his cookie with her, her mother gives him a piece of candy. The girl starts sharing her treats with her friends when they come over in the hopes of getting a similar reward. The girl's learning to share is an example of .
a) classical conditioning
b) operant conditioning
c) contingency theory
d) observational learning

Option B

Explanation:

Operant conditioning is a type of conditioning that logically appreciates positive behaviours mostly based on rewards of the fact that someone has carried out an act but just to keep such positive act with such person, you engaged in a reward system such that when such person does that act again they should expect a reward.

Relating to the passage above, it is obviously a operant conditioning, the sister has seen what her mother does to her brother when he carries such act, she wants to emulate such act to get reward this is an example of operant conditioning.