GWD语法一道 不理解答案选B

20allen

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.
 
 more research was needed to determine that balloon angioplasty preceded with ultrasound was or was not any better for heart attack patients than  
 
 more research was needed for determining whether or not balloon angioplasty preceded by ultrasound is any better for heart attack patients than is  
 
 that more research was needed to determine whether balloon angioplasty preceded by ultrasound is any better for heart attack patients than  
 
 that more research was needed to determine that balloon angioplasty preceded with ultrasound was any better for heart attack patients than  
 
 that more research was needed for determining that balloon angioplasty preceded by ultrasound is or is not any better for heart attack patients than is

20allen

我感觉C更好点儿 不知道是不是我那版的答案有问题？