42. In variable costing, when does fixed manufacturing overhead become an expense? Never In the period when the product is sold In the period when the expense is incurred At the time when units are produced A) B) C) D) 43. In full costing, when does fixed manufacturing overhead become an expense? A) B) C) D) In the period when all other fixed costs are expensed In the period when the product is sold In the period when the expense is incurred At the time units when are produced