Which of the following is the dependent variable?A. TimeB. Purity of waterC. Amount of Alka-SeltzerD. Temperature

To determine the dependent variable, we need to identify the factor that is being measured or observed in response to changes in other variables.

Looking at the options provided, we can see that A. Time, B. Purity of water, C. Amount of Alka-Seltzer, and D. Temperature are all potential variables.

Out of these options, the dependent variable is the one that is expected to change or be influenced by the other variables.

In this case, the dependent variable is B. Purity of water. This means that changes in the other variables (time, amount of Alka-Seltzer, and temperature) are expected to have an effect on the purity of water.