In His Speech About Registering to Vote, Dan Explains the New

In his speech about registering to vote, Dan explains the new legislation that allows voter registration to coincide with driver's license renewal. But he concludes by stating that anyone who is notregistered should immediately register in time for the next election. Finally, Dan reiterates: "Everyone please register to vote; it's your right and your duty as a citizen." What aspect of effective conclusions has Dan utilized?

A) an appeal to respond on the part of the audience
B) a personal reference to his own experience
C) an effective summary of main points in a speech
D) an inspirational appeal or challenge to the audience