Simplify : 343 × 49216 × 16 × 81 = ?

Answer: Option A

$$\begin{array}{rl}& \frac{343\times 49}{216\times 16\times 81}\\ & =\frac{7^3\times 7^2}{6^3\times 2^4\times 3^4}\\ & =\frac{7^{\left(3+2\right)}}{6^3\times {\left(2\times 3\right)}^4}\\ & =\frac{7^5}{6^3\times 6^4}\\ & =\frac{7^5}{6^{\left(3+4\right)}}\\ & =\frac{7^5}{6^7}\end{array}$$