The best answer would be Letter B - to entertain.
The author merely would like to provide amusement to the readers at his expense. It certainly does not persuade, explain, nor inform anything since it states - <span>But why bother with the descriptions; you’ve probably already grasped the idea!</span> - which could be taken as a witticism.
Him being giant (giant bladder)
Well you have to research what and how it was in 1863 and see if you can get access any of Lincoln's writing and compare the two.
Wow, that was good. I'd put more rhyming words depending on the poem you want it to be, but all in all great work.