Prater Company has provided the following data: units sold 300,000 this year 250,000 last year sales revenue 1,300,000 this year 1,050,000 last year cost of goods sold 910,000 this year 735,000 last year gross margin 390,000 this year 315,000 last year selling and admin expenses 272,000 this year 260,000 last year NOI 118,000 this year 55,000 last year The best estimate of the company's variable selling and administrative expense per unit is: A. $4.17 per unit B. $0.91 per unit C. $0.96 per unit D. $0.24 per unit