Now, what are they? men at all? or small moveable forts and magazines, at the service of some unscrupulous man in power? which of these rhetorical devices does thoreau use here? a- metaphor b- rhyme c- meter d- parallelism

The rhetorical device that Thoreau uses here is A) Metaphor

Metaphor describes a subject or objects as a different one or makes a comparison between them as if the were quite similar.

Rhyme is the use of repetition in one or two words more commonly at the end of each line

Meter creates a sound pattern in writing through the use of stressed and unstressed words being this organized to go one and one.

Parallellism uses repetitive structures in sentences.