Answer:
A good argumentative speech could be what's better; cats or dogs. It's a basic question but you could do actually research seeing which animal makes people happier, which one is cheaper, etc. But really anything as long as you are backed up by good information.
I hope this helped! Not 100% if that's what you were asking
While none of these sentences is particularly horrible, I would say that B is the best example of faulty coordination--if you note that the verbs switch from past to present tense within the same sentence, it draws attention in a very awkward way. Each clause could be it's own fully developed sentence, with more detail. The remaining sentences work well as stand alone sentences, and are congruent in structure and content.
B. Situational Irony
is the answer to this question.