You perform an experiment in which you take 16 pots of strawberry plants and give half of them 1 gm of ammonium nitrate per liter of water and the other half receive only water. Each group is then split in half again, and exposed to either 8 or 16 hours of light each day. You monitor the height of the plants for 4 weeks. You observe that plants grown in ammonium nitrate and 16 hours of light grow taller than no ammonium nitrate and 8 hours of light. Which of the following are dependent variables in this experiment?

Dependent variable is the effect that is being measured in an experiment while independent variable is the cause of that effect. Hence, dependent variable is not controlled or changed.

According to this question, height of the plants is the effect of the amount of ammonium nitrate and light. Hence, it defines the output or end result of the variation that is being studied.