If x = y = z, then ( x + y + z )^2x^2 + y^2 + z^2 is?

Answer: Option B

$$\begin{array}{rl}& \frac{{\left(x+y+z\right)}^2}{x^2+y^2+z^2}\\ & \text{Assume }x=y=z=1\\ & \iff \frac{{\left(1+1+1\right)}^2}{1+1+1}\\ & \iff \frac{9}{3}\\ & \iff 3\end{array}$$