Researchers are conducting a study to determine the effects of zinc supplements on the human immune system.The study involves providing pills that contain zinc to one group of human subjects and pills that do not contain zinc or other active ingredients to another group of people.The pills that do not contain zinc are
A)antidotes.
B)supplements.
C)probiotics.
D)placebos.

Question

Quizplus · Accepted Answer

The pills that do not contain zinc or other active ingredients are placebos. Placebos are commonly used in studies to provide a control group for comparison with the group receiving the active treatment.

Researchers Are Conducting a Study to Determine the Effects of Zinc