How does sentence 6 need to be changed? (6) I admit that I had enjoyed sharing a room with my little brother for the last six years.
A. Change admit to admitt
B. Change that to it
C. Change had enjoyed to have enjoyed
D. Insert a comma after brother

The answer is C.

If you put a comma after brother it creates a comma splice sentence. The sentence is complete without the comma.

Had is referring to the past.
Have is referring to now.

It can’t be A because it’s spelled wrong.
It can’t be B because that simple doesn’t make sense in the sentence.
It can’t be D because you’d create a comma splice.

So, the answer is C

A. they give the reader hope. if the whole book was dark & unhopeful it’d be a little less interesting, little moments make it more interesting to read because then you want to know what happens. if it’s all dark there’s no point in reading if you already know the outcome of it.