Many calculators have a [reciprocal](https://artofproblemsolving.com/wiki/index.php/Reciprocal) key $\boxed{\frac{1}{x}}$ that replaces the current number displayed with its reciprocal.  For example, if the display is $\boxed{00004}$ and the $\boxed{\frac{1}{x}}$ key is depressed, then the display becomes $\boxed{000.25}$.  If $\boxed{00032}$ is currently displayed, what is the fewest number of times you must depress the $\boxed{\frac{1}{x}}$ key so the display again reads $\boxed{00032}$?
$\text{(A)}\ 1 \qquad \text{(B)}\ 2 \qquad \text{(C)}\ 3 \qquad \text{(D)}\ 4 \qquad \text{(E)}\ 5$
Let $f(x)=\frac{1}{x}$.  We have
\[f(f(x))=\frac{1}{\frac{1}{x}}=x\]
Thus, we need to iterate the key pressing twice to get the display back to the original $\rightarrow \boxed{\text{B}}$.