Morpheme is the

The correct option is smallest unit of meaning that cannot be broken up.

Step-by-Step Explanation:

1. Understanding a Morpheme:
In linguistics, a morpheme is defined as the smallest meaningful grammatical unit in a language. This means it carries meaning and cannot be divided into smaller meaningful elements without altering or destroying its meaning.

2. Example of Morphemes:
Consider the word "unbreakable":
- "un-" (prefix meaning "not")
- "break" (root word meaning "to fracture")
- "-able" (suffix meaning "capable of being")
Each of these parts is a morpheme because each carries a distinct meaning and cannot be broken down further into smaller units of meaning.

3. Distinction from Other Units:
- A phoneme is the smallest unit of sound (e.g., /b/, /k/), but it does not carry meaning on its own.
- A morpheme is the smallest unit of meaning.
- Words and phrases are made up of one or more morphemes.

Therefore, a morpheme is the smallest unit of meaning that cannot be broken up further.