It costs CK Manufacturing $18 of variable and $6 of fixed costs to produce one photo tame which normally sells for $50.A foreign wholesaler offers to purchase 4,500 frames at $20 each. CK would incur special shipping costs of $3 per frame the order were accepted. CK has sufficient unused capacity to produce the 4,500 frames. the special order is accepted, what will be the effect on net income? $4,500 decrease $31,500 decrease $4,500 increase $90,000 increase