Which one of the following word parts means "to control or stop"?

The word part that means "to control or stop" is stasis. In medical terminology, "stasis" derives from the Greek word "stasis," which means to stand or to stop. It is often used to describe a state in which there is no movement or a pause in processes, such as blood flow or cell growth. This term is frequently seen in various medical contexts, such as "homeostasis," which refers to the regulation of internal conditions in the body to maintain a stable, constant environment.

In contrast, the other word parts provided have different meanings. For example, "myc/o" pertains to fungi, "stomy" relates to the creation of an opening (often surgically), and "trich" refers to hair. Understanding these prefixes and suffixes is crucial in medical language to accurately interpret diagnoses, procedures, and treatments. Thus, stasis is the appropriate choice when looking for a term that signifies controlling or stopping.