$\text{a) A.}$

$\frac{3^3\cdot 81\cdot {27}^2}{{\left(3^3\cdot 9\right)}^2}=\frac{3^3\cdot 3^4\cdot {\left(3^3\right)}^2}{{\left(3^3\cdot 3^2\right)}^2}=\frac{3^3\cdot 3^4\cdot 3^6}{{\left(3^5\right)}^2}=\frac{3^{3+4}\cdot {\left(3^2\right)}^3}{{\left(3^5\right)}^2}=$