From the given options, select the figure of speech (poetic device) used in expression:

Break, Break, Break open till they break the town

Alliteration

The correct answer is alliteration.

Alliteration is a figure of speech in which words that have the same initial consonant sound are placed close together. In the expression "Break, Break, Break open till they break the town," the repeated consonant sound is "b." This creates a sense of urgency and power, as the reader is hearing the sound of the waves crashing against the shore.

The other options are incorrect. Metaphor is a comparison between two things that are not literally alike. Personification is the attribution of human qualities to inanimate objects or animals. Simile is a comparison between two things using the words "like" or "as."