This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General physiology, Subject name: Physiology
Energy is required in 
Select and explain. 
A. Diffusion, B. Osmosis, C. Active transpo, D. None
C: Active transpo
Answer: C: Active transpo 
Explanation: The passage of substances against their electrical and chemical gradient at the expenditure of energy is called active transpo. (REF: TEXTBOOK OF MEDICAL PHYSIOLOGY GEETHA N 2 EDITION, PAGE NO - 6)