The best transition to add at the beginning of the third sentence is the following:
C. In addition.
Considering that the sentence introduces information that follows and agrees with the previous sentence, ‘in addition’ is the best transition as it specifies that the sentence will add more reasons for volunteering.
The "rattling off my plans" one
I'd choose "revise the structure of your essay by making the progression more logical."
Out of all the given answers that one makes most sense
D.
Anytime the word most is used with an adv. it makes it superlative
I think the answer is "In 1867, the United States bought Alaska from Russia for $7 million". When you ask the question "when" the question is asking about time. In this excerpt, when is answered by "in 1987". while the sentence supported it is the event that happened during that time, which is " The US bought Alaska from Russia for $7 million.