Suppose the elements $$X$$ and $$Y$$ combine to form two compounds $$XY_2$$ and $$X_3Y_2$$. When 0-1 mole of $$XY_2$$ weighs 10 g and 0-05 mole of $$X_3Y_2$$ weighs 9g, the atomic weights of $$X$$ and $$Y$$ are

A

60, 40

B

20, 30

C

30, 20

D

40, 30