Which of these options is a metaphor? giving brainliest to correct answers.

which of the following excerpts from "the significance of the frontier in american history" is a metaphor?

a. the existence of an area of free land, its continuous recession, and the advance of american settlement westward, explain american development.

b. the american frontier is sharply distinguished from the european frontier-a fortified boundary line running through dense populations.

c. it strips off the garments of civilization and arrays him in the hunting shirt and the moccasin.

d. behind institutions, behind constitutional forms and modifications, lie the vital forces that call these organs into life and shape them to meet changing conditions.

personally, i narrowed it down to:

c " strips off the garments of civilization"

or

d "that call these organs into life."

can't decide which one, .