If someone runs a marathon through a desert while eating pretzels and not drinking water, their plasma osmolarity: a) rises and becomes hypertonic to the interstitial and intracellular fluid compartments. b) rises and becomes hypotonic to the interstitial and intracellular fluid compartments. c) decreases and becomes hypertonic to the interstitial and intracellular fluid compartments. d) decreases and becomes hypotonic to the interstitial and intracellular fluid compartments.

a) rises and becomes hypertonic to the interstitial and intracellular fluid compartments.

Explanation:

The plasma osmolarity of a human body is the determination of the balance of electrolytes in the body as well as the balance of water present in the body.

The weather conditions in the desert is very high causing the temperature to be very hot. When a person runs in the desert they tend to sweat and lose water and when they eat pretezels without drinking water, they became seriously thirsty and very dehydrated.

This causes the plasma osmolarity of their body to increase and becomes hypertonic to the interstitial and intracellular fluid compartments. This causes the body cells to shrink or reduce in size and they lose water( in humans , they begin to sweat).

it will increase due to the time span