Mei wants to study whether heart rate increases more during certain exercises than during others. she designs an experiment to test the heart rates of classmates in the morning and in the evening for three days, immediately after doing jumping jacks, doing push-ups, or running in place. what is the dependent variable in this experiment?

The correct answer would be heart rates.

In an experiment, the dependent variable refers to the variable that is being tested by the scientists or any researcher.

For example, in this case, the student wants to determine the effect of exercise on the heart rate.

Thus, heart rate would be the independent variable and the type, frequency, or intensity would come under independent variable.

i believe it would cause an increase of percipitation, though i could be wrong. so i would say b is the answer.