The correct option is A S={1,2,3,4,5,6}
The sample space of an experiment or a random trial is the set of all possible outcomes or results of that experiment.
When we roll a die, the possible outcomes are 1,2,3,4,5 and 6. These possible outcomes make up the sample space S.
S={1,2,3,4,5,6}
Therefore, option (a.) is the correct answer.