Answer:
Choice B is correct
Step-by-step explanation:
Using the properties of exponents the expression can be simplified so as to eliminate the negative powers;
[tex]a^{-2}=\frac{1}{a^{2} }[/tex]
This component thus shifts to the denominator
[tex]a^{-7}=\frac{1}{a^{7} }[/tex]
This component thus shifts to the numerator
[tex]b^{-1}=\frac{1}{b}[/tex]
This component thus shifts to the numerator
The final simplified expression is thus B
