Benjamin Company Had the Following Results of Operations for the Past

Benjamin Company had the following results of operations for the past year:
$$\begin{array} { l r l r } \text { Sales } ( 16,000 \text { units at } \$ 10 ) & & \$ 160,000 \\\text { Direct materials and direct labor } & \$ 96,000 & \\\text { Overhead (20\% variable) } & 16,000 & \\\text { Selling and administrative expenses (all fixed) } & 32,000 & ( 144,000 ) \\\hline \text { Operating income } & & \$ 16,000 \\\hline \end{array}$$ A foreign company offers to buy 4,000 units at $7.50 per unit.In addition to variable manufacturing costs,selling these units would increase fixed overhead by $600 and selling and administrative costs by $300.Assuming Benjamin's productive capacity is 16,000 units per year and it accepts the offer,its profits will:

A) Decrease by $10,000.
B) Decrease by $10,900.
C) Decrease by $6,000.
D) Increase by $9,100.
E) Increase by $4,300.