(19)12 × (19)8 ÷ (19)4 = (19)?

Answer: Option E

$$\begin{array}{rl}& \frac{{\left(19\right)}^{12}\times {\left(19\right)}^8}{{\left(19\right)}^4}\\ & =\frac{{19}^{\left(12+8\right)}}{{\left(19\right)}^4}\\ & =\frac{{\left(19\right)}^{20}}{{\left(19\right)}^4}\\ & ={\left(19\right)}^{\left(20-4\right)}\\ & ={\left(19\right)}^{16}\end{array}$$
Hence the missing number = 16