If Helen Can Paint One Room in the Time It

If Helen can paint one room in the time it takes her to bake 40 cakes and Josh can paint one room in the time it takes him to bake 60 cakes, which of the following is correct?

A) The opportunity cost of painting is higher for Helen.
B) The opportunity cost of baking cakes is lower for Josh.
C) Helen's opportunity cost of painting one room is equal to 1/40 of a cake.
D) Josh's opportunity cost of baking one cake is equal to painting 60 rooms.
E) The opportunity cost of cakes cannot be computed.