Which line from "lather and nothing else." best reveals internal conflict?
a. to cover my nervousness, i went on honing the razor. b. he evidently took it for granted that i was on the side of the existing regime. c.he looked younger, several years younger than when he had come in. d. and it would be so easy to kill him. he deserves it. or does he? no!

The correct option is D.
In literature and drama, authors usually create conflict in order to make the readers interested in their stories. There are two basic types of conflict, these are internal and external conflict. External conflict refers to a struggle between a literary character and an outside force such as another character or nature. Internal conflict on the other hand refers to a psychological struggle that is going on in the mind of a character in order to decide whether to carry out an action or not.
The sentence in option D is an example of internal conflict because the character is struggling within his mind and trying to make up his mind whether to kill or not to kill a particular person.  

I believe it is D. The person is conflicted on whether or not to kill him and keeps arguing with themselves.