Answer:
The dependent variable is the time people take to get out of the room.
Step-by-step explanation:
The independent variable in a study is the factor researchers control or change with the objective of affecting the dependent variable. The dependent variable is, thus, what is being measured by the study, the factor that may or may not be affected by the independent variable. With that in mind, we can safely say that, in the scenario described, the independent variable is releasing ten spiders into a room. This is the change introduced to affect something. What is being affected, the dependent variable, is therefore the time people take to get out of the room.