Question

Groups of two's are selected from a group of four represented by the A, B, C, D. Which of the following represent the sample space

Answer 1

The sample space consists of all possible subsets of size $2$. We consider samples without replacement. The order of elements does not matter. $\Omega=\{\{A,B\},\{A,C\},\{A,D\},\{B,C\},\{B,D\},\{C,D\}\}$.