Answer:
D-water vapor
Step-by-step explanation:
In its biogeochemical cycle, water (H2O) passes through the three states of matter: solid, liquid and gas. Upon reaching the gaseous state, this substance forms water vapor, one of the main components of atmospheric air, invisible, of variable shape and volume.
Water vapor is fundamental to the maintenance of the most diverse forms of life on Earth. First, the substance acts directly on the temperature regulation of the planet's atmosphere, attenuating the incidence of infrared rays on the surface. In addition, water vapor is also responsible for the condensation and precipitation of rains: the water from rivers, lakes, glaciers and oceans evaporates through the action of the sun, condenses (changes from gaseous to liquid) in the upper layers high in the atmosphere and gives rise to clouds, which then precipitate in the form of rain.
The amount of water vapor present in the atmospheric air directly influences human health conditions. The relative humidity of the air, a factor that varies according to the presence of water vapor in the atmosphere, acts directly on the hydration of the respiratory system and the eyes, therefore, low values of this substance can cause allergies, dryness of the skin and mucous membranes, epistaxis, crises bronchitis, asthma, among other complications.