Why does air at 75% relative humidity and 30°C make your skin feel stickier than air at 75% relative humidity at 10°C?
A.
Warm air rises while cold air falls.
B.
The warmer air contains less water vapor per unit of volume.
C.
The warmer air contains more water vapor per unit of volume.
D.
Moist air has lower density than dry air does.

A warm air does always rise and cold air falls

the glands which are associated with each description is given below:

pancreas - is an endocrine and exocrine gland that secretes juices with enzymes for digestion. salivary glands- with protection and digestion in the mouth. liver- secretes bile for digestion.   lachrymal glands - secrete tears to moisten eyes and protect them from particles and infection.   sweat gland -regulates water, salt, and temperature. oil glands - to form a protective barrier on the skin.   goblet cells - secrete mucus for protection.