Select the correct answer.

Which person is likely to make the most effective presentation?

A. Ava wears the latest fashions, thinks that preparing beforehand is a waste of time, and tends to talk down to people.
B. James is a casual dresser, always runs behind schedule, likes to speak extempore, and tends to rush through his presentations quickly.
C. Kevin dresses formally, takes a lot of care with his preparation, focuses on one person in the audience throughout, and tends to ramble.
D. Olivia dresses neatly, rehearses what she has to say beforehand, and takes care to speak clearly.
E. Marcus dresses as unobtrusively as possible, speaks very softly, reads from prepared notes, and avoids looking at the audience.