I don't see that (b) violates any rules of grammar -- it's just not so idiomatic (not to me, anyway). This is common with prepositions. Often there's one (or more) prepositions that "sound right", and others that don't sound quite so right, even though there may be no obvious reason why.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.