Need in english
read the passage.

from john f. kennedy’s inaugural address
"so let us begin anew—remembering on both sides that civility is not a sign of weakness, and sincerity is always subject to proof. let us never negotiate out of fear. but let us never fear to negotiate. let both sides explore what problems unite us instead of belaboring those problems which divide us. let both sides, for the first time, formulate serious and precise proposals for the inspection and control of arms—and bring the absolute power to destroy other nations under the absolute control of all nations. let both sides seek to invoke the wonders of science instead of its terrors. together let us explore the stars, conquer the deserts, eradicate disease, tap the ocean depths, and encourage the arts and commerce. let both sides unite to heed in all corners of the earth the command of isaiah—to “undo the heavy burdens . . and let the oppressed go free.”and if a beachhead of cooperation may push back the jungle of suspicion, let both sides join in creating a new endeavor, not a new balance of power, but a new world of law, where the strong are just and the weak secure and the peace preserved."

how does the repetition of the phrase, “let both sides,” add to the persuasive power of the speech?

a. it emphasizes the idea that there are many challenges ahead.
b. it reminds the audience that kennedy is addressing only two people.
c. it reminds the audience that kennedy is taking sides in the conflict.
d. it emphasizes the idea that all people should work together.

i think its d. can someone confirm this or correct me?