which of the following is true? a. product costs are recorded first when constructing an income statement b. period costs are expense faster than product costs c. product costs always decrease taxable income in the period incurred d. all overhead is inventory, but not all inventory is overhead e. A & B f. A & C g. A & D h. A,B & C i. A, B & D j. B, C, & D k. A, B, C & D l. None of the above