单项选择题

Why did Merck & Co. Inc. pulled Vioxx from the market this September.

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.