Two Groups of People Were Tested to Determine Whether Garlic

Two groups of people were tested to determine whether garlic lowers blood cholesterol levels.One group was given 800 mg of garlic powder daily for four months and exhibited an average 12% reduction in the blood cholesterol.The other group was not given any garlic and after four months averaged a 3% reduction in cholesterol.The group that was not given the garlic was the __________ group.

A) peer
B) test
C) treatment
D) control
E) double-blind