Intercostal nerves arise from spinal segments:
T1–T12 (B) is the right choice. This sits at the heart of Peripheral 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: T1–T12 is the option that correctly names the structure, process, or principle asked for in Peripheral Nervous System. That reasoning supports T1–T12. 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 T1–T12 from memory, then reveal the letter — that habit builds real recall for Peripheral 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.