Hi Dlareh,
This is a great question and a great stimulus. It's a Method of Reasoning question, but what is it really asking us in the answer choices? In Answer Option (D) which is initially appealing, we are called upon to identify Graham's conclusion,
not the Philosopher's conclusion. This is huge. The philosopher's conclusion that "we should not be persuaded by Graham’s argument" is different from Graham's conclusion that "the best life is a life that is full of activity." So the question becomes does "the claim that at least sometimes when sleeping, people are truly happy, even though they are not doing anything" attack that conclusion? After all, would that conclusion not allow for some sleep in our lives? Rest would probably be allowed even a life "full of activity." Does the philosopher actually attack the premise that "a person is truly happy only when doing something?"
It does.
But here's the real kicker, the philosoher does not seek to disprove Graham's logic as false,
merely that it is "unpersuasive." Which tells us that the philosopher is not challenging the logic, he is challenging Graham's premise! Those two reasons are why Answer (B) is the correct choice.
Thanks and I hope this helped!
