Rapid gas exchange can be accomplished more easily in air than in water because a. the o2 content of water is higher than that of air b. o2 diffuses more rapidly in water than air c. water is more dense and viscous d. water holds less o2 per unit volume e. more energy is required to move air than to move water

C. water is more dense and viscous

Explanation:

Rapid gas exchange can be accomplished more easily in air than in water because water is more dense and viscous.

Gases have the greatest ease of diffusion of their respective particles, as occurs in air, since their molecules have higher speeds and have more distance from each other than liquids.

The molecular diffusion rate in liquids is much less than in gases. The molecules of a liquid are very close (liquids are more dense and viscous) to each other compared to those of a gas, then the gas molecules hits with the molecules of the liquid with more frequency and this causes that the gas moves slower than in other gas (for example in air).