For any positive x, y and z if x is n% of y and z is m% of y

For any positive x, y and z if x is n% of y and z is m% of y then what percentage must x be of z?
A. (n/m)%
B. (m n)%
C. (100 / [m n]) %
D. (100 m/n)%
E. (100 n/m)%