Helen gives up the opportunity to bake 40 cakes for each room she paints; Josh can paint one room in the time it takes him to bake 60 cakes. The opportunity cost of a cake for Josh is
A) painting one room
B) painting 1/40 of a room
C) painting 1/60 of a room
D) painting 2/3 of a room
E) painting 3/2 of a room