Answer:
B
Step-by-step explanation:
[tex]\frac{a^{m}}{a^{n}}=a^{m-n}\\\\\\(a^{m})^{n} =a^{mn}[/tex]
[tex]\frac{(4m^{2}n)^{2}}{2m^{5}n}=\frac{4^{2}(m^{2})^{2}n^{2}}{2m^{5}n}\\\\\\=\frac{16m^{4}n^{2}}{2m^{5}n}\\\\\\=\frac{8m^{4}n^{2}}{2m^{5}n}\\\\\\=8m^{(4-5)}n^{(2-1)}\\\\\\=8m^{-1}n[/tex]