Plz help! This is for English!!

For Part A: Right answer is Option C.

For Part B: Right answer is Option F.

For Part B (II): Right answer is Option I.

Explanation:

For Part A:  

They help us in processing nutrients and vitamins that is needed for our body.

For Part B:  

They help process nutrients and vitamins that is needed for our body. This fact was claimed by "The American Gut Project", which was started to understand the life of bacteria that lives in our digestive system.

For Part B (II):

They help us in processing nutrients and vitamins that is needed for our body. While many bacteria are very dangerous, we should perhaps be carefuul to eliminate the good from the bad.

i think the answer is c

what passage are you referring to