What Is the Correct Formula for the Direct Material Usage

Multiple Choice

What is the correct formula for the direct material usage variance?

A) (The direct materials that should have been used in actual production - the actual direct materials used in actual production) x the actual cost for one unit of direct material.
B) Actual expenditure on direct materials used in actual production - expected expenditure on direct materials used in actual production.
C) What the direct materials used in actual production should have cost - what the direct materials used in actual production actually cost.
D) (The direct materials that should have been used in actual production - the actual direct materials used in actual production) x the standard cost for one unit of direct material.