12. The three components added together to arrive at the total cost for a job under time- and-material pricing are ('3' A, the variable labor charge, the materials themselves, and the material loading charge. ' B. the labor charge, the materials themselves, and the material loading charge. 0 C, the xed labor charge, the materials themselves, and the material loading charge. 0 D, the labor charge, the materials themselves, and the variable material loading charge