Amplitude of graded potential depends on:
Stimulus strength (B) is the right choice. This sits at the heart of Action potential: 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: Stimulus strength is the option that correctly names the structure, process, or principle asked for in Action potential. That reasoning supports Stimulus strength. 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 Stimulus strength from memory, then reveal the letter — that habit builds real recall for Action potential.
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.