In this excerpt from "Colonialism in the United States" by Henry C. Lodge, which word is closest in meaning to the word indelibly?

Long after the world to which it belonged has vanished, a habit of thought will live on, indelibly imprinted upon a race or nation, like the footprint of some extinct beast or bird upon a piece of stone.

A. forcefully

B. mysteriously

C. permanently

D. vaguely

"Long after the world to which it belonged has vanished, a habit of thought will live on, indelibly imprinted upon a race or nation, like the footprint of some extinct beast or bird upon a piece of stone ... "

Looking at the context clues around the word we notice ... "imprinted," and "footprint of some extinct beast ... " we can infer that the word indelibly is most closely related to permanently. Thus, your answer, C.