Option A gives you nearly as much decision-making, as you still have to choose which Feat to take (and to a lesser extent, which ability scores to improve). And as a bonus, you get to have a more customized character with more options in and/or out of combat.
I mean, attributes are hardly a choice. One will just boost attributes one is focusing on to begin with. From what I have seen in Solasta 5e feats aren't many, nor are terribly interesting. As such giving player option to pick too many of them might result in less customisation in a way - give players too much and they don't have to choose anymore. As it is, in 5e many feats come already with boost to an attribute, so it's is clearly meant as a trade off.
As I said I would prefer a different system alltogether, but 5e is clearly designed around having to pick one or the other.
