Volume $$A$$ equals one fourth of the sum of the volumes $$B$$ and $$C$$, while volume $$B$$ equals one sixth of the sum of the volumes $$A$$ and $$C$$. The ratio of volume $$C$$ to the sum of volumes of $$A$$ and $$B$$ is

A

$$2\colon3$$

B

$$9\colon10$$

C

$$7\colon12$$

D

$$12\colon23$$