Which of the following statements is correct?

A An adverse direct material cost variance will always be a combination of an adverse material price variance and an adverse material usage variance B An adverse direct material cost variance will always be a combination of an adverse material price variance and a favourable material usage variance C An adverse direct material cost variance can be a combination of a favourable material price variance and a favourable material usage variance D An adverse direct material cost variance can be a combination of a favourable material price variance and an adverse material usage variance