Add the fractions $\frac{2}{12}+\frac{9}{12}$ and write the result in simplest form.

A) $\frac{1}{8}$
B) $\frac{11}{24}$
C) $\frac{3}{4}$
D) $\frac{11}{12}$
E) $\frac{3}{2}$

To add these fractions, we need a common denominator, which in this case is 12. We can see that the second fraction already has a denominator of 12, but the first fraction has a denominator of 6. We can rewrite the first fraction with a denominator of 12 by multiplying both the numerator and denominator by 2: $$\frac{2}{12}+\frac{9}{12}=\frac{2\cdot 2}{12\cdot 2}+\frac{9}{12}=\frac{4}{24}+\frac{9}{12}$$ Now we have a common denominator, so we can add the fractions: $$\frac{4}{24}+\frac{9}{12}=\frac{4+18}{24}=\frac{22}{24}$$ Finally, we can simplify by dividing both the numerator and denominator by their greatest common factor, which is 2: $$\frac{22}{24}=\frac{11}{12}$$ Therefore, the answer is D.