A manufacturer sells a product whose price–demand equation is p(q)=50−0.1q (price p in dollars, quantity q in units). A new per-unit tax of \2paidbythesellereffectivelyreducesthepricereceivedtop(q)-2.ThetotalcostofproducingqunitsisC(q)=10q+1{,}000.Whatisthemarginalprofit,indollarsperunit,whenq=200$?
a) 2
b) −2
c) 0
d) −4