The value of 5.71 × 5.71 × 5.71 - 2.79 × 2.79 × 2.79/5.71 × 5.71 + 5.71 × 2.79 + 2.79 × 2.79 is :

Answer: Option B

Given expression :
$$\begin{array}{rl}& \frac{{\left(5.71\right)}^3-{\left(2.79\right)}^3}{{\left(5.71\right)}^2+5.71\times 2.79+{\left(2.79\right)}^2}\\ & =\left(\frac{a^3-b^3}{a^2+ab+b^2}\right)\\ & =\frac{\left(a-b\right)\left(a^2+ab+b^2\right)}{\left(a^2+ab+b^2\right)}\\ & =\left(a-b\right)\\ & =\left(5.71-2.79\right)\\ & =2.92\end{array}$$