Two costs at Bradshaw Company appear below for specific months of operation. Month Amount Units Produced Delivery costs September $ 40,000 40,000 October 55,000 $ 84,000 Utilities September 60,000 40,000 60,000 October 126,000 Which type of costs are these O A. Delivery costs and utilities are both variable. O B. Delivery costs are mixed and utilities are variable. O C. Delivery costs and utilities are both mixed. O D. Utilities are mixed and delivery costs are variable