Mathematics

Problem

The value of

\binom{50}{0} \binom{50}{1} + \binom{50}{1} \binom{50}{2} + \dots + \binom{50}{49} \binom{50}{50}

, where

{}^n C_r = \binom{n}{r}

, is a.

\binom{100}{50}

\binom{100}{51}

\binom{50}{25}

\binom{50}{2}