Question

my/o is an example of: multiple choice the prefix at the beginning of some words. the foundation of the word that provides its meaning. the vowel that joins a root to another root or to a suffix. the combination of a root and a combining vowel. the ending of some words.

Explanation:

In medical - terminology and linguistics related to word - building, a combining form is a combination of a root and a combining vowel. My/o is a combining form where "my" is the root related to muscle and "o" is the combining vowel. It is not a prefix (which comes at the start of a word to modify meaning), not just a root (as it has the combining vowel attached), not just a vowel for joining, and not an ending.

Answer:

the combination of a root and a combining vowel.