This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Basic Concepts, Subject name: Pathology
Most common cause of cell Injury at level of cells? 
Select and explain. 
A. Hypoxia, B. Ischemia, C. CO poisoning, D. Anemia
A: Hypoxia
Answer: A: Hypoxia 
Explanation: Hypoxia Deficiency of oxygen,which causes cell injury by reducing aerobic oxidative respiration Extremely impoant and most common cause of cell injury and cell death. Causes:- Reduced blood flow (ischemia) Cardiorespiratory failure Anemia or carbon monoxide poisoning or after severe blood loss (Decreased oxygen-carrying capacity of the blood). Depending on the severity of the hypoxic state, cells may adapt, undergo injury, or die.