Which of the following is a word root?

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

A word root is a basic word part that often comes from Greek or Latin.

A word root is a basic word part that often comes from Greek or Latin.

The option that corresponds to a word root is "a basic word part that often comes from Greek or Latin."

A word root forms the core or foundation of a word and usually originates from the Greek or Latin languages. It carries the central meaning of the word and is not modified by any other word parts. For example, in the word "hypnotize," the word root is "hypno-," which means sleep.

As for the other options:
- An affix added to the end of a word root is called a suffix. It modifies the meaning or creates a new word. For example, in "careless," the suffix "-less" changes the root word "care" to mean without care.
- A word part added at the beginning or end of a word that changes the word's meaning is called a prefix or a suffix, respectively. They alter the original word by adding a different meaning or context. For example, in "unhappy," the prefix "un-" changes the meaning of "happy" to convey the opposite.

Therefore, the correct option is the one that identifies a word root as a basic word part that often originates from Greek or Latin.