"That is well said, said Arthur, now have I a sword, now will I wage battle with him, and be avenged on him." Avenged means took revenge. Option D is correct.
On the one hand, avenge is a verb which means "to inflict a punishment or penalty for an injury or a wrong." In this light, the word avenge connotes a pursuit of justice for someone other than one’s self. To avenge may mean to punish a person when someone is seeking to vindicate someone else, or as a way of justice.
On the other hand, evenge is both a noun and a verb and commonly means the act of taking vengeance for injuries or wrongs; retaliation.
Revenge suggests a more personal type of vengeance and is usually driven by feelings of anger and resentment.