Arthur Company had the following data for the year just ended: Sales: 4,000 units Sales price: $60 per unit Variable cost: $18 per unit Fixed costs: $42,000 If the company wants to increase its total contribution margin by 40% in the next year, all other factors remaining the same, it will need to increase its sales by: a) $50,400 b) $67,200 c) $72,000 d) $96,000