The primary circadian clock in mammals is located in the:
Pick C: Set point. Thinking about Structure and Function of Nervous System in a practical way — what the structure does, or what the process achieves — leads you here. Clinically and academically, the same logic shows up again and again: location matters here: Set point is the structure or site that matches the description. Hence Set point is correct. Treat this as a building block for the rest of Structure and Function of Nervous System; neighbouring topics often reuse the same principle. Keep a one-line summary card for this idea and revisit it before the paper; short, repeated review beats long cramming sessions.
Ref: Animal physiology is Unit 7 of the CSIR NET Life Science Syllabus, covering core body systems. It accounts for roughly 10% of the total marks in Sections B and C.