does she chat with friends on the Internet?Once a week.A. How longB. How oftenC. H

问题补充：

--- does she chat with friends on the Internet?

--- Once a week.

A. How long

B. How often

C. How many times

D. How much

答案：

A. How long

(答案→)B. How often

C. How many times

D. How much

解析：How long多长；How often多久一次；How many times多少次；How much多少钱。根据下文，每周一次。可知上文提问的是频率，故选B。