Which of the following numbers has the smallest prime factor?
$\mathrm{(A)}\ 55 \qquad\mathrm{(B)}\ 57 \qquad\mathrm{(C)}\ 58 \qquad\mathrm{(D)}\ 59 \qquad\mathrm{(E)}\ 61$
The smallest prime factor is $2$, and since $58$ is the only multiple of $2$, the answer is $\boxed{\mathrm{(C)}\ 58}$.