The correct answer is D. Alliteration
Step-by-step explanation:
In poetry, the word "alliteration" refers to a stylistic and sound device that consists on the repetition of consonant words usually as two or more words that are placed together or almost together begin with the same consonant sound. This sound device differs from assonance because the assonance consists of the repetition of vowel sounds and from rhyme because rhyme usually occurs between the last words of different verses. Considering this, in the case of "Mary sat musing on the lamp-flame at the table / Waiting for Warren" the sound device is alliteration that occurs in "Mary sat musing" with the repetition of the sound "M" at the beginning of two words that placed almost together and in "Waiting for Warren" with the repetition of the sound "W".