Answer
Among a group $d+1$ integers there are at least 2 integers with exactly the same remainder when divided by $d$.
Work Step by Step
The remainder when divided by integer $d$ will be of type {0,1,2,3,....,d-1}
We can see the number of possible remainders when divisor is $d$ will be d.
So, according to pigeonhole principle, among a group of $d+1$ integers there are two integers with same remainder when divided by $d$.
