Which of the following is a phonotactic rule that characterizes English?

• A. All glides in English are voiced by default.
• B. The sound sequence /dl/ may not occur at the beginning of a word.
• C. English has /ð, θ/ in the repertoire whereas many languages omit these sounds.
• D. The /p/ is aspirated in the onset except after /s/.

Answer: (B)

Phonotactics governs which sound sequences are allowed in a language, especially at word boundaries. For English, the set of possible word-initial consonant clusters is restricted, and a cluster like /dl/ simply does not occur at the start of a word. That makes this statement a genuine phonotactic rule of English, because it encodes a prohibition on a specific onset sequence and reflects how speakers reliably pronounce words without such an initial cluster.

Other statements describe features that aren’t about permissible sequences in word-initial positions: the glides’ voicing is a general phonological property, the presence of certain phonemes concerns inventory rather than allowable onsets, and the aspiration pattern is an allophonic distribution rather than a constraint on allowable word-initial sequences. So the /dl/ onset prohibition best captures a phonotactic rule that characterizes English.