What is the definition of the prefix "micro"?

The prefix "micro" is derived from the Greek word "mikros," which means "small." In the context of medical terminology and various scientific disciplines, it denotes something very tiny or on a small scale. For example, in medical terms, a microscope is an instrument used to view small objects that are not visible to the naked eye. This understanding of "micro" as relating to the small size of items is why the correct choice is "small."

The other options stem from different roots and meanings that do not align with the definition of "micro." Understanding prefixes like "micro" helps in grasping more complex medical terms and their implications in various fields.