Question

read the excerpt from president roosevelt’s state of the union address.
i cannot prophesy. i cannot tell you when or where the united nations are going to strike next in europe. but we are going to strike—and strike hard.
the primary purpose behind roosevelt’s words in this excerpt is to
impress the public with emotional diction.
inspire the public to join the military.
convince the public of america’s strength.
encourage viewers to remain active.

Explanation:

Roosevelt's statement acknowledges uncertainty about the timing/location of strikes but emphasizes a firm, strong upcoming strike. The core message is to assure the public of America's resolve and capability to act forcefully, rather than focusing on emotional language, military recruitment, or urging public activity.

Answer:

C. convince the public of America's strength.