First, understand the objection.
Second, give the answer from revelation.
Third, show how the correctness of the answer really depends on whether or not we have modern revelation through modern prophets.
Fourth, explain that whether or not we have modern prophets and revelation really depends on whether the Book of Mormon is true.
Uh...
This 'logic' is just a bit circular; don't you think?
Well that is what I think but, if you are not literate then you wouldn’t recognize it, as you couldn’t possibly have deductive reasoning at hand.