Hi to you both!
I like that you are using conditionals here, pj, but I would make a small adjustment. I would clearly show the structure of the argument. You want to distinguish the premise(s) from the conclusion in order to clearly understand what the principle should strengthen.
Premise: Commitment that benefits none

deserves no praise
Conclusion: Commitments

morally neutral
We need a principle that helps the idea that all commitments are morally neutral. The evidence we have so far is that there are some commitments that don't deserve praise. It's a pretty big jump to prove that all commitments are morally neutral, but remember here that we aren't justifying the conclusion. We only need to help it in some way.
Answer choice (A): This answer choice is describing things that are true about morally neutral commitments. But they don't support the idea that ALL commitments are morally neutral. In fact, because it says that morally neutral commitments must fall into at least one of two specific categories, it weakens the idea that all commitments are morally neutral.
Answer choice (B): This also gives us a reason to think that some commitments are not morally neutral, so we would eliminate it.
Answer choice (C): This answer choice gets us to the idea that some commitments are morally neutral, but that's not quite far enough. It doesn't support that ALL are morally neutral. While this is a better choice than both answer choice (A) and answer choice (B), it still doesn't support our conclusion that all commitments are morally neutral.
Answer choice (D): This says certain commitments aren't virtuous, but that's not saying all commitments are morally neutral.
Answer choice (E); This is phrased conditionally. Any commitments deserve no praise

all commitments are morally neutral. This is somewhat strange in phrasing or even in concept. It's a large jump from there's a commitment that is undeserving of praise, therefore ALL commitments are morally neutral. But this follows the logic. It directly connects our premise, which established that there are some commitments that are not deserving of praise, to our conclusion, that all commitments are morally neutral.
Hope that helps you both!