18r4s5+6/-32s+3=?

A)6r2s5+3
B)-6r2s5+3
C)6r2s4+3
D)-6r2s4+3

as written, this makes no sense

There is no "r" in the divisor, so how does the power of r get reduced from 4 to 2? Repost with parentheses, and say r^4 for the 4th power of r.