Simplify the Following Algebraic Expression and Express Your Answer Using $b ^ { - 1 } b ^ { - 4 }$

Multiple Choice

Simplify the following algebraic expression and express your answer using positive exponents only. $b ^ { - 1 } b ^ { - 4 }$

A) $\frac { 1 } { b ^ { 5 } }$
B) $b ^ { - 5 }$
C) $b ^ { 5 }$
D) $\frac { 1 } { b ^ { 7 } }$
E) $\frac { 1 } { b ^ { - 3 } }$