The three medians RQ, SP and TN of $$\triangle$$RST intersectat point O. If the area of $$\triangle$$RST is 48 cm$$^2$$, then the area of the quadrilateral SQON is:

A

20 cm$$^2$$

B

12 cm$$^2$$

C

16 cm$$^2$$

D

18 cm$$^2$$