Answer:
Control group
Step-by-step explanation:
During research study, subjects may be classed into the two different groups namely, the experimental and control group. The experimental are those subjects which are given the treatment to be used for the study or undergoes treatment while the control group are not given the treatment, they are also called placebo group. They are used to examine variation between the treatment and without the treatment. Hence, the cups of water which salt was added are the experimental group, the cup of water without salt are the control group.