Every time maricella goes to work in the morning, she notices that her dog sulks in the corner of the room and looks very sad. over several weeks, she notices that the dog gets unhappy when she picks up her car keys, immediately before leaving the house. which phenomenon of learning best describes the dog's behavior?
(a)- classical conditioning
(b)- operant conditioning
(c)- both a & b

The answer is a)  classical conditioning

Explanation:

Classical conditioning is also known as Pavlovian  conditioning and is a learning procedure in which a biologically potent stimulus (e.g. food) is paired with a previously neutral stimulus (e.g. a bell). It also refers to the learning process that results from this pairing, through which the neutral stimulus comes to elicit a response (e.g. salivation) that is usually similar to the one elicited by the potent stimulus. Here the stimulus is picking up the key is associated with being abandoned.

The role of the learner here, the dog, is passive. But, it has a voluntary response - an emotionally motivated action - to stimulations like Maricella leaving to work or taking the car keys, what denotes that the response is post stimulation, naturally.

  Therefore, letter "c" is the option that best satisfies the proposed question, once the phenomenon could be majorly described as classical conditioning, but, has an inclusion of the voluntary response factor that is generally imputed to the operant conditioning, hence not being possible to describe the situation through only one learning process.