Find the expression that is equilvelent

For this case we have the following expression:
 -18a ^ -2b ^ 5 / -12a ^ -4b ^ -6
 For power properties we have:
 -18a ^ (- 2 - (- 4)) b ^ (5 - (- 6)) / - 12
 Rewriting we have:
 18a ^ (- 2 + 4) b ^ (5 + 6) / 12
 3a ^ (- 2 + 4) b ^ (5 + 6) / 2
 3a ^ 2b11 / 2
 
 3a ^ 2b11 / 2
 option 3

25% increaseplus i think decrease i only know increase: ((