Which option is written correctly and contains an instance of contested usage?

a. “since the forecast calls for rain, nobody with any sense isn’t going hiking.”
the sentence contains a double negative.

b.“my brother called to say he needed a ride, but he didn’t say where he was calling from.”
the sentence ends with a preposition.

c.“my sister and brother changed their minds about coming to visit over the holidays.”
the sentence uses the possessive pronoun “their” for a singular antecedent.

d.“so that he would not be disturbed, i tried to uncover carefully the sleeping baby.”
the sentence contains a split infinitive.

i believe it is "he will always remain extremely timid" if its wrong sorry

1. read the following excerpt from franklin d. roosevelt's "fireside chat 19":

on the other side of the picture, we must learn also to know that guerilla warfare against the germans in, let us say serbia or norway, us; that a successful russian offensive against the germans us; and that british successes on land or sea in any part of the world strengthen our hands.

remember always that germany and italy, regardless of any formal declaration of war, consider themselves at war with the united states at this moment just as much as they consider themselves at war with britain or russia. and germany puts all the other republics of the americas into the same category of enemies. the people of our sister republics of this hemisphere can be honored by that fact.  

the true goal we seek is far above and beyond the ugly field of battle. when we resort to force, as now we must, we are determined that this force shall be directed toward ultimate good as well as against immediate evil. we americans are not destroyers — we are builders.

analyze the effectiveness of this excerpt. how does it function within the speech as a whole? how does the structure of the excerpt to convey the speech's purpose and key points? support your argument with evidence from the speech. (10 points)