\(A=8^2\cdot324=8^2\cdot18^2=144^2=\left(12^2\right)^2=12^4\)
\(B=27^3\cdot9^4\cdot243=\left(3^3\right)^3\cdot\left(3^2\right)^4\cdot3^5=3^9\cdot3^8\cdot3^5=3^{22}\)
\(C=6^2\cdot36^4\cdot216^2=6^2\cdot\left(6^2\right)^4\cdot\left(6^3\right)^2=6^2\cdot6^8\cdot6^6=6^{16}\)
\(D=3^4\cdot81^2\cdot9^5=3^4\cdot\left(3^4\right)^2\cdot\left(3^2\right)^5=3^4\cdot3^8\cdot3^{10}=3^{22}\)