The expression ((x²*y)/(y⁴))(4/3) equals (xr)/(yt) where r, the exponent of x, is:___ t, the exponent of y, is:___
a. r = 8/3 t = -16/3
b. r = 8/3 t = -4
c. r = 16/3 t = 4
d. r = 4/3 t = -8/3