Final answer:
The term for the variable being measured in an experiment is the 'dependent variable'. It is affected by the manipulation of the 'independent variable', which is controlled by the researcher to study effects on the dependent variable.
Step-by-step explanation:
The term that matches the definition of 'the variable that is being measured in an experiment' is the dependent variable. In a scientific experiment, the dependent variable is the variable that is affected by the manipulation of the independent variable, which is the variable that the researcher changes or controls. The intent of manipulating the independent variable is to observe the effects on the dependent variable. For example, if a biologist is studying the effect of light intensity on plant growth, light intensity is the independent variable (because it's what the biologist changes), whereas plant growth is the dependent variable (because it's what is measured).
Control variables must be kept constant throughout the experiment to ensure that any observed effect on the dependent variable is due to the manipulation of the independent variable alone. Thus, the correct answer to the question is C. the dependent variable.