Concept:Parallelism is the repetition of similar grammatical structures to create balance and rhythm.Explanation:The underlined phrase uses a repeating structure: "forever on the move, forever vigilant" and "without drums, without gleaming uniforms."Each part follows the same pattern and grammatical form.This balanced repetition emphasises the idea and gives the sentence a rhythmic effect.It is not antithesis, allusion, or parody.Answer:C. parallelism