yup "A" is a straightforward choice ..
B) He's not countering him ..no where he says I disagree or what.
C) He doesn't point out any mistake..he's just citing another example.
D) He's not saying whether Whittaker's claim ir true or false
E) He's not explaining anything to him ..
Just stay inside the scope and don't presume anything beforehand ..
He's just citing an analogus situation and the result it wud generate ..
--I never think of future, it comes soon enough!!