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
Which factor does not affect the diffusion of substance through the cell membrane? 
Select and explain. 
A. Molecular size of the substance, B. Lipid solubility of the membrane, C. ATP generating capacity on both sides of membrane, D. Distribution of channels for the substance in the membrane
C: ATP generating capacity on both sides of membrane
Answer: C: ATP generating capacity on both sides of membrane 
Explanation: Diffusion occur without the expenditure of energy. It depend on the concentration of molecules. (REF: TEXTBOOK OF MEDICAL PHYSIOLOGY GEETHA N 2 EDITION, PAGE NO - 4)