Regarding Their Research on Weight Loss, Conlon and His Colleagues

Regarding their research on weight loss, Conlon and his colleagues weighed the participants on a standard digital scale at the beginning of the weight-loss period and once every week until the program ended.This exact procedure being used to represent the participants' weights is referred to as the

A) ​operational definition.
B) ​tentative theory.
C) ​null hypothesis.
D) ​contingent reinforcer.