Final answer:
The correct answer is C. Operational definition. An operational definition is a description of how researchers will measure the variables of interest in a study.
Step-by-step explanation:
The correct answer to this question is C. Operational definition.
An operational definition is a description of how researchers will measure the variables of interest in a study. It defines the concept in terms of concrete steps or observable conditions that can be objectively measured. By operationalizing the variables, researchers can collect data in a systematic and replicable manner.
For example, in a study examining the effects of tutoring on grades, one researcher might define a "good" grade as a C or better, while another researcher might begin with a B+. These operational definitions set limits and establish cut-off points to ensure consistency and replicability in the study.