Here's a thought.
Buy B. Much lower range but the ability to go to sea on small boats that the USMC actually want to use for helos. Or our own boats of which one might be available.
Buy C. If B falls over we don't care. If QECV falls over, err...we still don't care, let's stop talking about a Harrier replacement and claim we have bought DPOC. If C can't trap a wire or whatever the next problem is wrt ship integration can't be fixed - we still don't care. The crabs never wanted to go to sea anyway. At least we bought the one that goes the furthest.
Buy C.