I left for the office earlier than usual this mornings______traffic jam.

A、 in line with
B、 in case of
C、 for the sake of
D、 at the risk of

【正确答案】 B

【答案解析】本题考查介词词组辨析。A in line with符合，与…一致；B in case of万一，以防；C for the sake of为了…的好处，为了…利益；D at the risk of冒着…的危险；根据本题句意：今天早上我比以往更早动身去上班以防交通拥堵。因此本题选B。