Material usage variance is computed by:

The correct answer is: A. SQ – AQ

Material usage variance is the difference between the actual quantity of materials used and the standard quantity of materials that should have been used, multiplied by the standard price per unit of material.

The standard quantity of materials that should have been used is calculated by multiplying the standard quantity of output by the standard material usage per unit of output.

The actual quantity of materials used is the actual amount of materials that were used to produce the actual output.

The standard price per unit of material is the price that should be paid for each unit of material.

Therefore, the material usage variance is calculated as follows:

Material usage variance = (Standard quantity of materials that should have been used) – (Actual quantity of materials used)

= (Standard quantity of output × Standard material usage per unit of output) – (Actual quantity of materials used)

= (SQ × S) – (AQ)

= SQ – AQ