Which of the Following Is the Correct Formula for Elasticity $\frac {\text {\(\%\) change in price }} { \text { \(\%\) change in quantity}}$

Which of the following is the correct formula for elasticity of demand?

A) $\frac {\text {\(\%\) change in price }} { \text { \(\%\) change in quantity}}$
B) $\frac {\text {\(\) change in price }} { \text { \\ change in quantity}}$
C) $\frac {\text {\(\) change in demand }} { \text { \\ change in price}}$
D) $\frac {\text {\(\%\) change in quantity demanded }} { \text { \%change in price}}$
E) none of the above