Which of the Following Statements Is True

Which of the following statements is true?

A) A per unit cost that is constant at all production levels is a variable cost per unit.
B) Reported income under variable costing is affected by production level changes.
C) A per unit cost that is constant at all production levels is a fixed cost per unit.
D) Reported income under absorption costing is not affected by production level changes.
E) A cost that is constant over all levels of production is a variable cost.