- Fri Nov 27, 2020 7:10 pm
I think I'm misreading your post a bit, because answer choice (D) is actually the right answer.
I also don't think that your analysis of answer choice (D) shows that there's any problem with it. As you point out, answer choice (D) is basically a conditional: if a handwriting analyst claims that handwriting analysis is reliable, that person is irresponsible. I think you're pointing out that no handwriting analysts necessarily have to even claim reliability, so none have to be irresponsible. That's true; the sufficient condition may be true of no one. But that's terrible for the argument! If no handwriting analysts claim that handwriting analysis is reliable, then why should anyone regard it as reliable?
Answer choice (D) breaks handwriting analysts into two categories: those who do not claim it's reliable, and those who are irresponsible. So, if I wanted, as I should, to limit myself to responsible people, when gaining their opinions, I would find no analysts saying that handwriting analysis is reliable! If I wanted to find anyone who called it reliable, I'd have to talk only to irresponsible ones! So every good source on analysis is hesitating to claim reliability. How can I make a case for its reliability, then? This is why answer choice (D) weakens the argument.