I see what you're getting at with (B), since you've named the function which adds another 'thing' to think about. But I can anonymise it in modern Javascript:

  y = (x) => {return Math.max(2, x)}

To me that just looks nice, and it's clear how Math.max is being used. With the partial (A) I have to have some implicit knowledge of the function, where as in (B) or my version I can see how it's being used. Perhaps I'm a bit dis-functional.