Which of the following terms refers to letters that represent sounds in a language?

The term that refers to letters representing sounds in a language is graphemes. Graphemes are the smallest units in a writing system that correspond to sounds in spoken language. For example, in the English language, the letter "b" is a grapheme that represents the sound /b/. Similarly, combinations of letters such as "sh" represent a specific sound as well. Understanding graphemes is crucial in reading instruction because they are foundational to phonics and decoding skills.

In contrast, morphemes are the smallest grammatical units in a language that carry meaning, syllables are units of pronunciation that typically contain a vowel sound, and phonemes are the distinct units of sound in a language that can distinguish meaning but do not represent letters directly. Each of these terms plays a unique role in the study of language, but graphemes specifically deal with the relationship between written letters and their corresponding sounds.