Question

question 1 of 10
to test a new drug that has the potential of curing people of the common cold, a company asked human volunteers who were coughing and sneezing to participate in a clinical study. the objective of the experiment was to test whether the new drug could cure the volunteers in the experimental group of the common cold. but instead of two groups, these volunteers were randomly divided into three groups and treated as follows:

group	experimental group	control group #1	control group #2
orange juice	yes	no	no
bed rest	yes	yes	no

which of the following is the best explanation of why a second control group was included in this experiment?
a. to confuse anyone who is trying to steal their new drug and sell it as their own invention
b. to help researchers conclude that results are related to the new drug and not to the orange juice
c. to prove that the common cold cannot be cured

Explanation:

In scientific experiments, control groups are used to isolate the effect of the variable being tested. Here, with orange - juice being another factor, a second control group helps to ensure that any observed effects are due to the new drug and not the orange - juice.

Answer:

B. To help researchers conclude that results are related to the new drug and not to the orange juice