Final answer:
The dependent variable in an experiment is the one that is measured or observed and is affected by the independent variable, which the researcher manipulates.
Step-by-step explanation:
In an experiment, the dependent variable is the variable that is measured or observed (C). It is not manipulated by the experimenter but is affected by the manipulation of the independent variable. This independent variable is directly controlled or manipulated by the researcher, and it is the variable that is hypothesized to have an effect on the dependent variable. In experimental design, all other factors that might affect the dependent variable are held constant as control variables to ensure that any changes in the dependent variable can be attributed to the manipulation of the independent variable.