单选题 The motivation of rapists is now (acknowledged) to be a more complex matter (than being) formerly believed; it (has come) to be widely accepted that rape is not (necessarily) the result of sexual desire.

A. acknowledged
B. than being
C. has come
D. necessarily

【正确答案】 B

【答案解析】[解析] 此处完整形式为than (the motivation which) was formerly believed，省略主语。