Which of the following is a word root?

A. a word part added at the beginning or end of a word root that changes the word's meaning
B. an affix added at the beginning of a word root
C. a basic word part that often comes from Greek or Latin
D. an affix added to the end of a word root

C. a basic word part that often comes from Greek or Latin

The correct answer is C. A word root is a basic word part that often comes from Greek or Latin.

The correct choice is option C. A word root is a basic word part that often comes from Greek or Latin. To determine the answer, it is important to understand the definitions of the given terms.

Option A refers to a word part added at the beginning or end of a word root that changes the word's meaning. This is called a prefix or suffix.

Option B refers to an affix added at the beginning of a word root. This is also a prefix.

Option D refers to an affix added to the end of a word root. This is called a suffix.

Therefore, the correct choice for a word root is option C, which is a basic word part that often comes from Greek or Latin.