Calculating Standard Deviation for Continuous Series

Q.

If the variance of $1,2,3,4,...,10$ is $\frac{99}{12}$, then the standard deviation of $3,6,9,12,...,30$ is

1. $\frac{297}{4}$

2. $\frac{3}{2}\sqrt{33}$

3. $\frac{3}{2}\sqrt{99}$

4. $\frac{\sqrt{99}}{12}$

5. $\frac{3\sqrt{3}}{2}$