— does Jane exercise?—Four times a week.A. How soonB. What timeC. How longD. How often

问题补充：

— does Jane exercise?

—Four times a week.

A. How soon

B. What time

C. How long

D. How often

答案：

A. How soon

B. What time

C. How long

(答案→)D. How often

解析：How soon多久；What time几点，什么时间；How long多长；How often多久一次。根据下文，一周四次。可知上文问的是频度，故选D。