Create an equivalent expression of the photo.
( / is a fraction)
A: 1.6 power of 4 / 1.7 power of 3
B: 1.7 power of 28 / 1.6 power of 21
C: 1.7 power of 3 / 1.6 power of 4
D: 1.6 power of 21 / 1.7 power of 28
