Simplify the Following Algebraic Expression and Express Your Answer Using $\left( \frac { 20 y ^ { 5 } } { 5 y ^ { - 2 } } \right) ^ { - 1 }$

Multiple Choice

Simplify the following algebraic expression and express your answer using positive exponents only. $\left( \frac { 20 y ^ { 5 } } { 5 y ^ { - 2 } } \right) ^ { - 1 }$

A) $\frac { 1 } { 4 y ^ { 7 } }$
B) $\frac { 4 } { y ^ { 7 } }$
C) $\frac { 1 } { 4 y ^ { 3 } }$
D) $4 y ^ { 3 }$
E) $4 y ^ { 7 }$