What is the function of serous fluid?

A. It helps the stomach and other organs maintain neutral buoyancy within body cavities, even during fluctuations in atmospheric pressure, or when gases, such as oxygen or methane, are present in varying ratios.
B. It prevents the organs from drying out when in contact with air.
C. It aids in the repair of damaged organs.
D. It enables organs, such as the heart and the stomach, to slide across cavity walls and each other without friction.

D . It enables organs such as the heart and stomach, to slide across cavity walls and each other without friction

Explanation:

Serous fluid is a yellow transparent liquid which is usually found in body cavities. The serous fluid serves as a lubricant to prevent internal organs such as the heart, lungs and so on, from being rubbed against each other.

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.