Because two things can't happen at the same time, the first question can only be expressed by pVq. Of course, there is nothing wrong with you using (┐p Vq)V(pV┐q) to express it, because these two things can't happen at the same time, either one or the other, that is to say, when P is correct, Q must be wrong, that is, Q and ┐p are equivalent, so there is no need to express ""at this time.

But the second question must be (┐p Vq)V(pV┐q), otherwise the meaning of "only one choice" cannot be expressed, because P and Q are no longer contradictory, so if you want to express the meaning of only one choice, you can only use this expression (┐p Vq)V(pV┐q).

It's long, but it's all in its own language. I hope it is easier to understand. ...