GMAT Sentence Correction (SC) | Researchers agreed that the study of new treatments for

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

---