If the Total Materials Variance (Actual Cost of Materials Used

If the total materials variance (actual cost of materials used compared with the standard cost of the standard amount of materials required) for a given operation is favorable,why must this variance be further evaluated as to price and usage?

A) There is no need to further evaluate the total materials variance if it is favorable.
B) Generally accepted accounting principles require that all variances be analyzed in three stages.
C) All variances must appear in the annual report to equity owners for proper disclosure.
D) It is done so that management can evaluate the efficiency of the purchasing and production functions.