Whereas, that I am a handless BIV is not ordinarily a salient counter-possibility to my having hands. So the truth of C′ is compatible with my ordinary claim to “know”, since the latter might strictly express the proposition that My having hands rather than my having had my hands amputated and replaced with prostheses is what explains why I believe that I have hands rather than that I’ve had my hands amputated and replaced with prostheses.