To determine the sample space \( S \) for the event where Dayshawn can choose two out of his four t-shirts labeled A, B, C, and D, we first note that we need to select combinations of two t-shirts without regard to the order in which they are chosen.
The choices of t-shirts can be represented as pairs. The combinations of two t-shirts from the four available options can be listed as follows:
- AB
- AC
- AD
- BC
- BD
- CD
Thus, the complete set of combinations is: \[ S = { AB, AC, AD, BC, BD, CD } \]
This means the correct representation of the sample space is: \[ S = { AB, AC, AD, BC, BD, CD } \]
So the choice that represents the sample space is: S = {AB, AC, AD, BC, BD, CD}