I'd say B, because of the sanitation, but A might work toooooooo, bt id go with A.
Reduce if, in your case, it means using less. Because that means you never have a need to do the others because nothing was ever “dirtied” For example like a plastic cup if you never drank out of it you can’t recycle it or reuse it or downsize it.
Blood type O can be given to anyone.
