Concept:Phonemes are the smallest distinct units of sound that can change the meaning of a word. The sounds 'th', 'ph', 'ch' each represent a single phoneme.
Explanation:A phoneme is a speech sound that distinguishes one word from another. For example, /th/ in "thin" changes the word compared to /ch/ in "chin".
The options are different linguistic units:
- A morpheme is the smallest meaningful unit (e.g., 'un' in 'unable').
- A grapheme is the smallest written unit (e.g., 'ee' in 'week').
- A lexeme is the smallest lexical unit (e.g., 'find' for 'finds', 'found').
- A phoneme is the smallest sound unit (e.g., /th/, /ph/, /ch/).
Since 'th', 'ph', 'ch' are sounds, not meaning units or written units, they are phonemes.
Answer:D. Phonemes