Juan used to be a fairly generous individual, but it seemed that whenever he loaned things to people, they were never returned, or they were returned broken. Consequently, Juan is no longer generous. Based on principles of operant conditioning, Juan's lack of generosity is MOST likely a result of:a. punishment. b. positive reinforcement. c. negative reinforcement. d. extinction.

(A) Punishment

Explanation:

 According to the given question, the Juan's lack of generosity is due to the result of punishment because whenever Juan is try to help others by giving them the things for use then, the people never returned or either they were given him with broken or bad condition.

 So, due to this situation the Juan is no longer kind or generous on the basis of the operant conditioning process as it is one of the form of learning in which the people may change their attitude and behavior due to some consequences.

 Therefore, Juan's lack of generosity is results into the punishment according to the operant conditioning as punishment is one of the key concept of operant conditioning process.

the first one is d and the second a