Which of the following terms refers to the act of swallowing?

The term that refers to the act of swallowing is derived from the suffix "-phagia." This suffix specifically pertains to the process of eating or swallowing food. For instance, conditions like dysphagia indicate difficulty swallowing, highlighting its direct connection to the act of swallowing itself.

In contrast, the other choices present different meanings. The suffix "-pnea" relates to breathing, "-tussie" refers to coughing, and "-tension" typically pertains to the state of being stretched or strained. Therefore, understanding the specific medical terminology is crucial, as the correct choice clearly delineates the action of swallowing in the context of anatomy and physiology.