A and C is right on the money.
Apart from a first-hand account from a good friend who now works in Cologne, how about this from a recent IATA press release:
IATA believes that EASA and the UK Civil Aviation Authority (CAA) should be allowed to initiate detailed technical discussions on the future relationship between the two bodies, with [IATA CEO Alexandre] de Juniac calling it "ridiculous" that formal discussions between the two bodies have not been allowed.
Full release may be found
here