B. It should be, "each of the men say", not says, because it's multiple men and not just one.
I think it would be the third
The two primary purposes for sending business messages are typically to __inform____ and ___persuade____.
The importance of using a variety of sentence structures is to change up your writing. To make the reader engaged in what you have to say. If your sentence structure is weak and does not vary the reader might get bored. It also better shows your topic.
hope this helps! have a good day!
