A、By air. B、By sea. C、Either by air or by sea. D、Neither by air nor by sea. B

M: Are you looking forward to your trip to Canada?
W: I can’t wait to see Canada, but I’m scared stiff of the journey. My husband insists on flying, but I want to sail. Planes make me nervous.
M: There’s nothing to be frightened of. How many planes fly across the Atlantic every day?
W: I’ve no idea. Hundreds, I suppose.
M: And how often do you hear of a crash? ... Once or twice a year?
W: Yes, but planes fly so high and fast that once is enough.
M: Look, there are more road casualties per day than air deaths per year. Air transport is really safe compared with road transport.
W: I’d still prefer to go by sea. Ships may not travel fast but at least you can relax; I’d love a trip on a luxury liner like the Queen Elizabeth Ⅱ.
M: It’s fine if you are a good sailor, but have you ever traveled far in a rough sea?
W: No, I’ve only bean in a boat once. I sailed down the River Thames on a sightseeing tour But in any case I’d rather be sea-sick than dead.