3 3 3........ is equal to = ?

Answer: Option B

Shortcut method:
When the question is in form
$$\begin{array}{rl}& \Rightarrow \sqrt{n\sqrt{n\sqrt{n}}}........\infty \\ & \Rightarrow \text{So }n\text{ is answer }\\ & \Rightarrow \text{3}\end{array}$$