Simplify the following.
$$81^{\frac{3}{4}}+\left[(20\div5 of 3 \times 6) + \left\{(8 \div 24 of 3) \times 4\right\} -10\div 5\right] - \left(\frac{1}{32}\right)^{-\frac{2}{5}}$$

A

$$24\frac{1}{4}$$

B

$$21\frac{1}{9}$$

C

$$27\frac{4}{5}$$

D

$$29\frac{4}{9}$$