Number obtained by reversing digits. Find the value satisfying a condition.

Number obtained by reversing digits. Find the value satisfying a condition.

Let $a$ and $b$ be two-digit integers such that $b$ is obtained by
reversing the digits of $a$. The integers $a$ and $b$ satisfy
$a^2-b^2=m^2$ for some positive integer $m$. Which could be value of $m$?
a) $30$
b) $31$
c) $32$
d) $33$