( 0.798 )^2 + 0.404 × 0.798 + ( 0.202 )^2 + 1 = ?

Answer: Option B

According to question,
$$\sqrt{{\left(0.798\right)}^2+0.404\times 0.798+{\left(0.202\right)}^2}+1$$
$$\Rightarrow \sqrt{{\left(0.798\right)}^2+{\left(0.202\right)}^2+2\times 0.202\times 0.798}+1$$
$$\Rightarrow \sqrt{{\left(0.798+0.202\right)}^2}+1\left[\because {\left(a+b\right)}^2=a^2+b^2+2ab\right]$$
$$\begin{array}{rl}& \Rightarrow \sqrt{{\left(1\right)}^2}+1\\ & \Rightarrow 1+1\\ & =2\end{array}$$