Answer:
C). Metaphor.
Step-by-step explanation:
Metaphor is demonstrated as the literary device that establishes an implicit comparison between two distinct things in order to explain and clarify a point to the readers. It assists the author or speaker to display that assists the readers to have a clear and comprehensive understanding.
In the given excerpt from Martin Luther King Jr's 'Nobel Price Acceptance Speech', 'metaphor' is employed to compare the two completely unrelated or contradictory ideas i.e. 'justice and an injured person' to explain the implicit similarity or resemblance between the two as they both are helpless. Thus, he displays a need to uplift the justice from this 'dust of shame to reign supreme.' Thus, option C is the correct answer.