The mean of three numbers $$\frac{a}{3}$$, b and c is the same as the mean of the numbers $$\frac{b}{3}$$,$$\frac{c}{3}$$ and x. The value of 3x is (where a, b, c are positive numbers):

A

b+c

B

a+2b+2c

C

a

D

a+3b+3c