Which of the following statements pertain to variable costing?

A. This method must be used for external financial reporting.

B. Fixed manufacturing overhead is attached to each unit produced.

C. The income statement not does disclose a company's contribution margin.

D. Variable manufacturing overhead becomes part of a unit's cost.

E. None of the other answers are correct.

Consider the following statements about absorption costing and variable costing: I. Variable costing is consistent with contribution reporting and cost-volume-profit analysis. II. Absorption costing must be used for external financial reporting. III. A number of companies use both absorption costing and variable costing. Which of the above statements is (are) true?

A. I only.

B. II only.

C. III only.

D. I and II.

E. I, II, and III.