The issue with (A) is that Lyle might say yes to this. We know that Carl would say yes for sure, and it's possible that Lyle would as well. In fact, it's likely that Lyle would say yes, but he'd still think that even if there is different pedagogical value, that there still exists value in teaching modernized plays. Thus, (A) is out. We need a definitive disagreement between the two speakers.