Which of the following drug is reported to be able to prevent colon cancer

A．Bextra can be used in heart surgery.
B．4 percent of those given placebo had an adverse event.
C．Celebrex worked as well as aspirin to prevent colon cancer.
D．Celebrex doubled or even tripled deaths from heart attack, stroke or heart failure.

A．Because they learned the results of Dr. Jeffery Draze's trail.
B．Because Vioxx has proved a useless drug in trails.
C．Because trails showed that Vioxx almost doubled the risk of heart attacks, strokes and other major adverse events.
D．Because Merck&Co. Inc. could not make any money from the drug.