As activity level decreases, unit variable cost: O A. increases proportionately with activity. O B. decreases proportionately with activity. O C. remains constant. O D. decreases by a fixed amount. Technical Engineering presently leases a copying machine on a monthly basis. The lease agreement requires a fixed fee each month in addition to a charge per copy. Technical Engineering made 2,400 copies and paid a total of $162 in rent in September and in October they paid $195 for 3,500 copies. Determine Technical Engineering's variable cost per copy. O A. $0.06 O B. $0.01 O C. $0.04 OD. $0.03