Which best describes the respiratory system?
the respiratory system allows for gas exchange, water and heat balance, and creation of sound and speech.
the respiratory system allows for gas exchange, heat balance, and secretion of hormones.
the respiratory system allows for water and heat balance, prevention of disease, and creation of sound and speech.
the respiratory system allows for water balance, muscular support, and passage for ingesting food.

The correct answer would be The respiratory system allows for gas exchange, water and heat balance, and creation of sound and speech.

Respiratory system is a set of organs primarily responsible for exchange of gases between blood and air or water.

Genrally, lungs (alveoli) and gills are the site of gaseous exchange in animals living on land and in organisms living in water respectively.

It removes carbon dioxide from the blood and adds oxygen to it.

This system is also associated with exchange of water, heat balance, and creation of sound and speech.

Water is exchanges in the forms of water vapors. Exhaled air usually contains higher volume of water vapors as compared to the inhaled air.

Increased respiratory rate (panting) increases evaporation which helps in thermoregulation (decreases body temperature).

Larynx (a part of respiratory tree) is associated with production sound and speech.

the fossil record provides evidence of a common ancestor to many species.