AHSME 1969 Problem 3

If $N$, written in base $2$, is $11000$, the integer immediately preceding $N$, written in base $2$, is: $\text{(A) } 10001 \text{(B) } 10010 \text{(C) } 10011 \text{(D) } 10110 \text{(E) } 10111$