Dorsal roots of spinal nerves carry:
Correct option is B, Sensory impulses only. In Peripheral Nervous System, the accurate description is Sensory impulses only, and that is what you should commit to memory. Keep the definition tight and the role clear — Sensory impulses only is the option that correctly names the structure, process, or principle asked for in Peripheral Nervous System. Then Sensory impulses only is the answer you can defend. Check yourself by covering the options and writing the answer first, then matching the letter — that builds confidence. If the wording feels dense, translate it into everyday language first, then map that plain sentence back onto Sensory impulses only.
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.