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 an favourable material usage variance

C. An adverse direct material cost variance will always be a combination of an favourable material price variance and an favourable material usage variance

D. An adverse direct material cost variance will always be a combination of an favourable material price variance and an adverse material usage variance

答案说是D. 可是我觉得是A. 不是 dirct material cost variace=meaterial price variace + material usage variace么？那当然是A不管怎么样都是对的亚

请教大家！！非常感谢！

An adverse direct material cost variance will always be a combination of an favourable material price variance and an adverse material usage variance..

always??不一定啊..不过要是按照题目就是当 material price variance 为

favourable时material usage 会增加..应该是这样,价格便宜,消耗量就大....