Identifying Dependent Variable in Plant Growth Experiment

A research study was conducted to determine the effect of sunlight exposure on plant growth. In the experiment, two groups of identical plants were used. Group A was placed in a sunny location and received 8 hours of sunlight each day, while Group B was placed in a shaded area with only 2 hours of sunlight daily. The plants were watered equally and monitored for 4 weeks. At the end of the study, the height of the plants was measured to evaluate their growth.

Which of the following describes the dependent variable in this experiment?