The digits 1, 2, 3, 4 and 9 are each used once to form the smallest possible even five-digit number. The digit in the tens place is
$\text{(A)}\ 1 \qquad \text{(B)}\ 2 \qquad \text{(C)}\ 3 \qquad \text{(D)}\ 4 \qquad \text{(E)}\ 9$
Since the number is even, the last digit must be $2$ or $4$. To make the smallest possible number, the ten-thousands digit must be as small as possible, so the ten-thousands digit is $1$. Simillarly, the thousands digit has second priority, so it must also be as small as possible once the ten-thousands digit is decided, so the thousands digit is $2$. Similarly, the hundreds digit needs to be the next smallest number, so it is $3$. However, for the tens digit, we can't use $4$, since we already used $2$ and the number must be even, so the units digit must be $4$ and the tens digit is $9, \boxed{\text{E}}$
(The number is $12394$.)