Final answer:
After getting a bad sunburn, before heading out for a day at the beach, Stanley slathers on sunscreen to avoid getting sunburned. In this case, Stanley's habit of using sunscreen has likely been acquired by way of A) Operant Conditioning.
Step-by-step explanation:
Operant Conditioning refers to a type of learning where an individual's behavior is modified by its consequences; the behavior may change in form, frequency, or strength. Stanley likely experienced discomfort from the sunburn, which served as a negative consequence, leading him to apply sunscreen in order to avoid the unpleasant outcome in the future. This type of associative learning is based on the principle of reinforcement or punishment.
Alternative learning processes mentioned in the question include Classical Conditioning, Observational Learning, and Habituation. However, since the motivation to use sunscreen came after an unpleasant experience and the subsequent behavior change was motivated by the desire to avoid that negative stimulus, Operant Conditioning is the accurate answer choice here. It is important to understand the various types of learning processes in Psychology as they help explain how behaviors are acquired and modified. So the answer is option a.