The correct option is (a) anoxia.
Explanation:
Respiratory centre controls the rate of respiration. It is located in medulla oblongata and pons. Anoxia is a condition in which there is a deficiency in oxygen reaching the tissues that is severe enough to damage the brain permanently. Anoxia results from low, atmospheric pressure at high altitudes, a shortage of circulating blood, red blood cells or haemoglobin or disordered blood flow, such as occurs in heart failure.
