The functional division responsible for involuntary motor responses is:
Autonomic nervous system (C) is the right choice. This sits at the heart of Structure and Function of Nervous System: the wording points straight to what is happening in the tissue or organ system. A useful study habit is to ask what the structure or process is for: the functional job described in the stem is exactly what Autonomic nervous system does in Structure and Function of Nervous System. That reasoning supports Autonomic nervous system. One solid sentence about why this works is enough for recall — you do not need a long essay for every MCQ. When you practise, cover the choices first, write Autonomic nervous system from memory, then reveal the letter — that habit builds real recall for Structure and Function of Nervous System.
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.