Control mediator and moderator variables – UGC NET Question

Statements A, B and C accurately define control, moderator and mediator variables, and F adds an important implication. A is true because researchers hold control variables constant to prevent them from confounding the relationship between independent and dependent variables. B correctly states that moderator variables change the strength or direction of this relationship, and C is right that mediators explain how or why an effect occurs. F is also true since identifying such variables helps develop more refined theoretical models, whereas D and E are false because not all extraneous variables are mediators and moderators are often crucial in educational research.

Option A:
Option A omits statement F and therefore fails to acknowledge how identifying mediators and moderators enriches theoretical understanding. Although A, B and C are correct, leaving out F means the combination does not include all the true statements identified in the item. Consequently, it is incomplete.

Option B:
Option B wrongly includes statement D, which asserts that all extraneous variables are mediators. Many extraneous variables do not function as mediators in a causal chain; they may simply add noise or bias. By grouping D with otherwise correct statements, this option becomes conceptually inaccurate.

Option C:
Option C is correct because it selects statements A, B, C and F, all of which align with standard definitions and implications in research design. It excludes D and E, which misrepresent extraneous variables and the relevance of moderators. Therefore this combination contains all and only the true statements.

Option D:
Option D omits statement A and includes D, making it doubly problematic. It loses the essential notion of a control variable and adopts the false idea that all extraneous variables are mediators. Such a combination cannot be considered correct.