The correct answers are B) bring people together at a social event C) to be amusing and D) convince the audience to support a cause.
Entertaining speech is used for these purposes: bring people together at a social event, to be amusing and convince the audience to support a cause.
The purpose of this kind of speech is so simple: to amuse and entertain your audience. To convey an idea in a funny way so it could be clearly understood and accepted. So if you are attending a fundraising event where they are going to ask for your help and money, what a better way to do it with class, in a funny and amicable way.