Which of the following is true of variance?

• A. Managers should interpret a favorable variance as "good news" or assume it means their subordinates performed well.
• B. A variance within an acceptable range is considered to be an "in-control occurrence" and calls for no investigation or action by managers.
• C. The purchasing manager secured a discount for buying in bulk with fewer purchase orders which results in unfavorable material price variance.
• D. Managers' performance must be evaluated solely on single variance.