( 8 - 4 - 2 ) Equals to = ?

Answer: Option B

$$\begin{array}{rl}& \left(\sqrt{8}-\sqrt{4}-\sqrt{2}\right)\\ & =2\sqrt{2}-2-\sqrt{2}\\ & =2\sqrt{2}-\sqrt{2}-2\\ & =\sqrt{2}(2-1)-2\\ & =\sqrt{2}-2\end{array}$$