Suppose $A>B>0$ and A is $x$% greater than $B$. What is $x$?
$\textbf {(A) } 100\left(\frac{A-B}{B}\right) \qquad \textbf {(B) } 100\left(\frac{A+B}{B}\right) \qquad \textbf {(C) } 100\left(\frac{A+B}{A}\right)\qquad \textbf {(D) } 100\left(\frac{A-B}{A}\right) \qquad \textbf {(E) } 100\left(\frac{A}{B}\right)$
We have that A is $x\%$ greater than B, so $A=\frac{100+x}{100}(B)$. We solve for $x$. We get 
$\frac{A}{B}=\frac{100+x}{100}$
$100\frac{A}{B}=100+x$
$100\left(\frac{A}{B}-1\right)=x$
$100\left(\frac{A-B}{B}\right)=x$.  $\boxed{\left(\textbf{A}\right)}$