AHSME 1968 Problem 33

A number $N$ has three digits when expressed in base $7$. When $N$ is expressed in base $9$ the digits are reversed. Then the middle digit is: $\text{(A) } 0 \text{(B) } 1 \text{(C) } 3 \text{(D) } 4 \text{(E) } 5$