Answer:
[tex]\dfrac{1}{b^{-n}}=b^n[/tex]
Step-by-step explanation:
One of the property of exponents is :
[tex]\dfrac{1}{x^a}=x^{-a}\\\\\text{or}\\\\\dfrac{1}{x^{-a}}=x^{a}[/tex]
In this problem, x = b and a = n
So,
[tex]\dfrac{1}{b^{-n}}=b^n[/tex]
Hence, the correct option is (b).