A regular triangular pyramid is cut by 2 planes which are parallel to its base. The planes trisects the altitude of the pyramid. Volume of top, middle and bottom part is $$V_1, V_2$$ and $$V_3$$ respectively. What is the value of $$V_1 : V_2 : V_3$$?

A

1 : 8 : 27

B

1 : 8 : 19

C

2 : 9 : 27

D

1 : 7 : 19