Bolton Business sells a product at a price of $$150.$ Its variable manufactured cost is $$24$ and the variable marketing cost per unit is $$17\mathrm{.}50$ with fixed cost per period of $$80,000.$ What would be the change in operating income under variable costs if sales increase from $10,000$ to $10,100$ units?

$$12,600$

$$10,850$

$$13,250$

Loss of $$69,150$