The critic isn’t addressing whether certain characters are entertaining. Instead, she’s addressing whether certain characters are realistic. (A) fails to prove that immoral characters with no attractive qualities make works of fiction unrealistic.

It doesn’t matter which qualities are appealing. Instead, the critic argues that not giving any attractive qualities to immoral characters would make fiction works unrealistic. (B) fails to prove that immoral characters with no attractive qualities are indeed unrealistic.

If all bad people have some attractive qualities in real life, this guarantees the critic’s conclusion that not giving immoral characters any attractive qualities would make fiction unrealistic.

The critic is arguing that portraying immoral characters as having no attractive qualities makes them unrealistic. It doesn’t matter whether those characters are difficult to emulate. (D) fails to establish whether all immoral people have some attractive qualities in reality.

It doesn’t matter whether it’s evident which qualities are meant to be attractive. Instead, we need to know whether not giving immoral characters any attractive qualities makes fiction unrealistic. (E) fails to show that all immoral people in real life have some attractive qualities.