A.\({3^x}{.3^y} = {3^{x + y}}\)
B.\({4^{\dfrac{x}{y}}} = \dfrac{{{4^x}}}{{{4^y}}}\)
C.\({\left( {{5^x}} \right)^y} = {\left( {{5^y}} \right)^x}\)
D.\({\left( {2.7} \right)^x} = {2^x}{.7^x}\)