Concept:Learning is the connection formed between a specific stimulus and a corresponding response.Explanation:Learning involves modifying behavior through experience and training.The key idea is that learning creates an association between a stimulus and a response, known as the S‑R bond.This bond is based on two principles: the law of contiguity (events occurring close in time get linked) and the law of effect (rewards or punishments strengthen or weaken the link).Learning is not just acquiring facts; it also includes lasting life experiences that change behavior.Thus, the core of learning is always the stimulus‑response connection.Answer:A. Response