#### Answer

D. $\frac{4}{11}$

#### Work Step by Step

The bag starts out with 12 marbles (2+4+6). After taking one out, you are left with $11$ marbles. With the remaining marbles, 4 are blue, 5 are green, and 2 are red. The probability of drawing a blue marble is equal to the number of blue marbles divided by the total number of marbles, or $\frac{4}{11}$, which is choice D.