What type of variable is typically affected by changes in the independent variable?

The dependent variable is the correct choice because it is defined as the variable that is observed and measured in an experiment to assess the effect of the independent variable. In other words, it is the outcome that researchers are interested in understanding or predicting. When a change is made to the independent variable, it is expected that the dependent variable will respond in some way, reflecting the relationship being studied. This is a fundamental concept in research design, where the independent variable is manipulated, and the effect on the dependent variable is recorded.

In contrast, control variables are factors that are kept constant to ensure that any changes in the dependent variable can be attributed solely to manipulations of the independent variable. These do not change in response to the independent variable. Constant variables also remain unchanged throughout the experiment but serve to provide a baseline for comparison. Extraneous variables are unwanted influences that can affect the dependent variable and may confound the results, but they are not inherently dependent upon changes in the independent variable.