Thesaurus is the tool where you can find synonyms for a word, and even antonyms.
Although you can find synonyms in a regular dictionary as well, thesauri are better when it comes to that.
C as it has a better view on the situation
<span>How does the author maintain the lively, active mood of "in Just"? </span><span>
A. by describing the children's voices</span>
We can't see underlining here, but here, I think this will be helpful:
"I read a novel" would be the intependent clause: it does not need the other one to be complete.
"until the guests arrived" is the subordinate clause: it needs the independent, main clause to be complete.