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
First cellular change in hypoxia 
Select and explain. 
A. Decreased oxidative phosphorylation in mitochondria, B. Cellular swelling, C. Alteration in cellular membrane permeability, D. Clumping of nuclear chromatin
A: Decreased oxidative phosphorylation in mitochondria
Answer: A: Decreased oxidative phosphorylation in mitochondria 
Explanation: Ref, Robbins 8/e p18;7/e p15;9/ep45