The sample space of an experiment is the set of all possible outcomes. When Sam rolls a fair six-sided die, the possible outcomes are the numbers on the faces of the die: 1, 2, 3, 4, 5, and 6.
Therefore, the sample space is: \[ {1, 2, 3, 4, 5, 6} \]
So the correct answer is: \({1, 2, 3, 4, 5, 6}\).