The idea is to multiply and divide the coefficients of terms and add and subtract the powers of the variable "x"
Here is it:
8*4/7 = 32 / 7
and
[tex] \frac{x^4 * x^3}{x^2} =x^{4+3-2}=x^5[/tex]
So, we can write the final form as follows:
[tex] \frac{32x^5}{7} [/tex]
which leads us to the choice A
Hope that helps