A middle school campus is shaped like a rectangle with a width of 1/4 mile and a length of 1/2 mile. A map of the campus has a width of 1/2 foot and a length of 1 foot. What is the ratio of the area in square miles of the campus to the area in square feet of the map? A) 1:4 B) 1:2 C) 2:1 D) 4:1