After Reading the Paragraph Below, Answer the Questions That Follow

question 2

Multiple Choice

After reading the paragraph below, answer the questions that follow.
Researchers set up a study to determine whether large doses of a nutritional supplement would shorten the length of time it takes to recover from a cold. Three thousand volunteers were split into two groups. For two weeks, members of group A took 3,000 mg of the supplement daily. Group B received 3,000 mg of a placebo. At the end of the two-week period, the researchers inserted live cold viruses directly into the noses of all the volunteers. The volunteers in both group A and group B continued to take their daily pills. All the volunteers got colds, and there was no significant difference in the length of time the colds lasted.
-Which was the experimental group?

• A)group A only
• B)group B only
• C)all 3,000 volunteers
• D)the researchers that inserted the cold virus