Which of the Following Is True Regarding Normal Costing

Which of the following is true regarding normal costing?

A) Normal costing assigns to products actual direct material and direct labor costs plus an amount representing "normal" manufacturing overhead.
B) Under normal costing,a firm derives a rate for applying overhead to units produced before the production period begins.
C) Under normal costing,a firm uses a predetermined overhead rate in applying overhead to each unit as the firm produces it throughout the year.
D) All of the answers are correct.