Beware of motivated stopping. If someone wants to do A, because B will happen, that is only the beginning. There are several directions it's worth exploring further, with one person exploring and another prompting them with questions such as these:

Will B actually happen (or be more likely to), given A?

What makes B a desired consequence? Some further consequence that it leads to? Some larger purpose for which B is a means? Or is B terminally desirable?

At some point one has to stop, but the very first consequences one thinks of may not be that point.