How does repetition of the phrase "we must” roosevelt achieve his purpose? it encourages the public to act with a united front. it demands that every citizen contribute in some way. it shows that the nation’s only choice is to fight. it explains the specific roles each citizen must play. its the first

The repetition of the phrase "we must" help Roosevelt achieve his purpose in the wat that it encourages the public to act with a united front. Option A is correct.

Repetition helps strengthen the listener's memory, repeating certain words and phrases in your speech makes a lasting impact. The repetition or restatement of an idea at intervals promotes clarity as well as it encourages the acceptance of an idea so that it is important t repeat and emphasize one idea.

It encourages the public to act with a united front.

Explanation:

The repetition of the phrase "we must” helps Roosevelt achieve his purpose of encouraging the public to act with a united front. These lines are from President Roosevelt's Union Address speech. An anaphora is the repetition of the same word or words at the beginning of successive sentences in a speech. In this way, key words are emphasized and the repetition makes the ideas easy to remember.  

the answer is irony!

i have a basic answer but if you want a more in depth