Choose the correct mathematical model for calculating profit.

Let q = production volume (quantity produced)

R = revenue per unit

FC = the fixed costs of production

MC = material cost per unit

LC = labor cost per unit P(q) = total profit for producing (and selling) q units

(i) P(q) = Rq - FC - (MC)q - (LC)q

(ii) P(q) = Rq + FC + (MC)q + (LC)q

(iii) P(q) = Rq + FC - (MC)q + (LC)q

(iv) P(q) = Rq + FC + (MC)q - (LC)q