can "rather" submodify superlatives?
He's ---- the most handsome man I've ever met.
D) a lot
It can modify comparatives, but quite modifies superlatives.
Modifying comparatives and superlatives is rare (or perhaps nonexistent) in AE.
It's common enough in the UK:
It was rather better than I'd been exepecting.
It was quite the worst dinner I have had in ages.