Which pair of italicized words shows a difference of one phoneme?

The correct answer illustrates a pair of words that differ by a single phoneme, which is the smallest unit of sound in a language. In the choice of "cap" and "nap," the difference lies in the initial sounds: "c" in "cap" and "n" in "nap." This change in the initial consonant represents a single phoneme substitution.

The other options do not demonstrate a similar one-phoneme difference. In "take" and "make," the difference is again in the initial sounds, where "t" and "m" are changed, making it one phoneme. However, the context provided indicates that this pair would not be the best fit given what you have pointed out. "Hat" and "hat" do not illustrate any phonemic difference, as they are identical words. For "met" and "set," the difference is also in the initial phoneme with "m" and "s," making it similar to the previous examples but still no better than "cap" and "nap." Thus, "cap" and "nap" are the most straightforward example that clearly shows a change by one phoneme in both simplicity and clarity.