Step 1: Assertion (A): the learner is central in effective learning, true by definition of learner-centred education.
Step 2: Reason (R): the extension agent's job is to build learning situations that guide the learner, also true.
Step 3: Link check: guiding situations around the learner is exactly why the learner stays central, so (R) explains (A).
Step 4: Both correct and linked, so the correct option is (1).