Which process involves the intake of air into the lungs?

Inhalation is the process that specifically refers to the intake of air into the lungs. During this process, the diaphragm and intercostal muscles contract, which causes the thoracic cavity to expand. This expansion reduces the pressure in the lungs compared to the atmospheric pressure, allowing air to flow in.

Understanding inhalation is crucial as it is the first step in the respiratory process, where oxygen is brought into the body for use in cellular respiration, a vital function for energy production in cells. Inhalation directly correlates with breathing, depicting how air enters the respiratory system, making it the most accurate term among the choices provided for the intake of air into the lungs.