This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory System Pa 1, Subject name: Physiology
Respiratory burst is related to: 
Select and explain. 
A. Hyperventilation after a period of apnea, B. Apnea after a period of hyperventilation, C. Sharp increase in O2 uptake and metabolism in neutrophils, D. None of the above
C: Sharp increase in O2 uptake and metabolism in neutrophils
Answer: C: Sharp increase in O2 uptake and metabolism in neutrophils 
Explanation: Neutrophil's cell membrane-bound enzyme nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is activated on contact with a pathogen. Activation of NADPH oxidase is associated with a sharp increase in O2 uptake and metabolism in the neutrophil (the respiratory burst) and generation of superoxide (O2-) by the following reaction: The combination of the toxic oxygen metabolites and the proteolytic enzymes from the granules makes the neutrophil a very effective killing machine.