Bonita Company produces flash drives for computers, which it sells for $$20$ each. The variable cost for each flash drive is $$4.$ During April, $780$ drives were sold. Fixed costs for April were $$2$ per unit for a total of $$1560$ for the month. How much does Bonita's operating income increase for each $$1000$ increase in revenue per month?

Not enough information to determine the answer.

$$15600.$

$$300.$

$$800.$