I would say "B." is the most appropriate for this passage.
If the appositive phrase is needed to define the meaning of a noun then <u>don't use a comma</u>, if the appositive phrase defines enough where it can stand by it's self alone then <u>use commas around it.</u>
Question #1 : Letter A.
Question #2 : Letter B.
Question #3 : Letter A.
Question #4 : I'm not really sure, but I think the best answer would be Letter C.
I hope this helps you !
Are there answer like a multiple choice question