At 9,000 direct labor hours, the flexible budget for indirect materials is $27,000. If $28,000 of indirect materials costs are incurred at 9,200 direct labor hours, the flexible budget report should show the following difference for indirect materials:

(a) $1,000 unfavorable.

(c) $400 favorable.

(b) $1,000 favorable.

(d) $400 unfavorable.