Which of the following correctly demonstrates the comparison of the four-variance method of factory overhead analysis to the two-variance method of factory overhead analysis?
a. The sum of the fixed and variable spending variances in the four-variance method is equal to the flexible-budget variance in the two-variance method.
b. The sum of the fixed and variable spending and variable efficiency variances in the four-variance method is equal to the flexible-budget variance in the two-variance method.
c. The sum of the fixed and variable spending, variable efficiency and production-volume variances in the four-variance method is equal to the flexible-budget variance in the two-variance method.
d. The fixed spending variance in the four-variance method is equal to the flexible-budget variance in the two-variance method.