What is iconoclasm? a. rejection of using religion in art b. the protestant’s prejudice towards catholics c. the smashing of religious imagery d. protecting religious imagery

Correct  c. The smashing of religious imagery.

Explanation:  

An "icon" is a religious image.  Coming from terms in Greek language, an "iconoclast" is an "image breaker."

Some of the more radical groups within the Protestant Reformation reacted in extremely strong ways against the way that the Roman Catholic Church revered images and relics.  The radical reformers wanted to purify the church of all such "idolatry," as they saw it.  So they began smashing statues and other artwork depicting saints, etc.

to act quickly in times of danger to the united states

because you have to act quickly if you want to live/survive.