please make sure calculated answer is an answer choice

Sun Brite has a new pair of sunglasses it is evaluating. The company expects to sell 7000 pairs of sunglasses at a price of $165 each and a variable cost of $117 each. The equipment necessary for the project will cost $365,000 and will be depreciated on a straight-line basis over the 5-year life of the project. Fixed costs are $310,000 per year and the tax rate is 40 percent. How sensitive is the operating cash flow to a $1 change in variable costs per pairs of sunglasses? $4200 -$4667 0-$4200 $3780 -$3780