Mathematics - Binomial Theorem Question with Solution | TestHub

The sum of the coefficients is obtained by setting $a=1$, $b=1$, $c=0$, and $d=1$. Thus, the answer is $(1+1+0+1{)}^8-(1+0+0+1{)}^8=3^8-2^8=6561-256=6305$. The correct option is A.