Process of elimination can help out here. Since 2 is an integer, and 3 is an integer, whatever goes under the √ sign needs to be a number that you can easily take a square root of (fractions are ok!). Rule out C, D, and E.

Now try out A and B. A gives you

$3\sqrt{\frac{2}{18}}=3\sqrt{\frac{1}{9}}=3*\frac{1}{3}=1$. Rule it out.

B gives you $3\sqrt{\frac{4}{9}}=3*\frac{2}{3}=2$.

Answer: B