Walter has exactly one penny, one nickel, one dime and one quarter in his pocket.  What percent of one dollar is in his pocket?
$\text{(A)}\ 4\% \qquad \text{(B)}\ 25\% \qquad \text{(C)}\ 40\% \qquad \text{(D)}\ 41\% \qquad \text{(E)}\ 59\%$
Walter has $1 + 5 + 10 + 25 = 41$ cents in his pocket.  There are $100$ cents in a dollar.  Therefore, Walter has $\frac{41}{100}\cdot 100\% = 41\%$ of a dollar in his pocket, and the right answer is $\boxed{D}$.