This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
Diffusion is inversely related to: 
Select and explain. 
A. Molecular size, B. Area, C. Concentration gradient, D. Solubility
A: Molecular size
Answer: A: Molecular size 
Explanation: Diffusion is directly propoional to area, solubility, concentration gradient It is inversely related to thickness and molecular size