The correct answer would be letter B. No revision is necessary. There is no revision needed in the sentence because the rules in using quotation marks and other punctuation marks are applied and they were placed correctly in the given sentence.
From my understanding all you are doing is converting liters to grams. It says you have one leader of hydrogen peroxide. 1 liter equals 1000 grams. And if it is asking how many grams are in 1 liter hydrogen peroxide then the answer would be 1000 grams
I believe it is telling you to write about the information you gathered during the interview <span />
Answer: He begin to think of ways to improve the lives in his community
Explanation
The answer is "He begin to think of ways to improve the live sin is community because in the text most the the passage identifies the problem, then he thinks about building a generator and the bigger battery.
Why the other answers are wrong
A is wrong because it tells us the solution not the central idea.
C identifies the problem, not the Central idea of the text.
D is wrong because it tells us his decision, it is better than the other answers but not the best.
