How might a manager get insight into the causes of a direct materials flexible-budget variance? OA. A flexible-budget variance for direct materials is based only on the efficiency variance. Therefore, a manager should inve cause of this variance to gain insight and find ways to make improvements. OB. A manager should subdivide the flexible-budget variance for direct materials into a price variance (that reflects the differe actual and budgeted prices of direct matarials) and an efficiency variance (that reflects the difference between the actual quantities of direct materials used to produce actual output). The individual causes of these variances can then be invest recognizing possible interdependencies across these individual causes. OC. A flexible-budget variance for direct materials is based only on the price variance. Therefore, a manager should investigat this variance to gain insight and find ways to make improvements. OD. A manager should subdivide the flexible-budget variance for direct materials int