[求助]XDF 1901-11

Researchers agreed that the study of new treatments for heart attack patients was extremely important but more research was needed to determine that balloon angioplasty preceded with ultrasound was or was not any better for heart attack patients than the balloon procedure by itself.

B. more research was needed for determining whether or not ballooon angioplasty preceded by ultrasound is any better for heart attack patients than is

C. that more research was needed to determine whether balloon angioplasty preceded by ultrasound is any better for heart attack patients than

answer: B

不应该加that 吗 ？  而且，B的whether or not 太罗嗦了吧？

我选的C