At higher elevations, as in the mountains, there is less oxygen content in the air. How would the body respond

Question

which one of these are the answers

the aortic bodies signal the breathing center to increase breathing rate

the breathing center in the brain would increase the breathing rate

carotid bodies in the lungs would signal the brain to decrease breathing rate

there is no mechanism for the body to respond to this phenomenon

Answer 1

The depth of respiration increases.

The body produces more red blood cells to carry oxygen.

Pressure in pulmonary capillaries is increased, "forcing" blood into parts of the lung which are not normally used when breathing at sea level.

The body produces more of a particular enzyme that causes the release of oxygen from haemoglobin to the body tissues.

Answer 2

The above answer is correct, but your question is flawed.

Oxygen content as a percentage does not change with elevation. You need to review the gas laws, especially Dalton's law of partial pressures.