Answer:
All of the above logically could be applied in this context; however, if you are to choose one, I would think your best bet is "Vary Tone and Emphasis."
Explanation:
There's a lot that goes into making a speech more enthralling for the audience, especially depending on what kind of presentation you're giving. Generally speaking, I believe the tone and emphasis are most important for all speeches, so that probably sounds like your best bet.
D. Can't be properly divided. :D
I can makes signes with my hands
I can make drawings
I can make stories
I can make pictures
I can make cake
I can make art
I can make messes
I can make fashion
I can make silly faces
I can make people laugh
I can make people smile
I can make my room tidy
I can make my mom and dad smile
I can make my mom and dad laugh
I can make my bed