An engaging and convincing speech definitely needs a speaker that is <u>passionate</u> about the topic. In addition, language must be <u>clear and accessible</u>; in other words, the speaker should speak plainly, even though he or she has <u>expert knowledge</u> in the topic. Finally, <u>stories</u> (the speaker's own stories, if possible) and <u>jokes</u> (or at least a good dose of sense of humor) are also important.
I think it's D ( sorry if I'm wrong)
