Answer:
Cup 1 acts as a control group.
Step-by-step explanation:
Control group: The group used in the experiment by the researchers in which no change in the variable is done. It is then set as a benchmark for the groups which are being tested.
We are given 4 groups which are being experimented for the flotation of an egg in water.
Since in Cup 1, there is no addition of salt
So, there is no change in the variables.
So, by definition of control group .
So, cup 1 acts as a control group since there is no change in the variable .
Hence, the correct answer is Option 1.
Cup 1 acts as a control group.