21. The decision by an athlete to take or not take performance enhancing drugs (PED) could be described as a Prisoner's Dilemma. Because the decision is taken in relation to what other athletes are likely to do, it can be evaluated in terms of Game Theory. Using this matrix (1) what is the Dominant Strategy of each athlete, (2) the Nash Equilibrium, and (3) Optimal Strategy if cooperation were possible? Assume that the PED causes harm to the health of the athlete in the long term as well as potential for fines, penalties and reputational damage. Mark Do not Use PED No Advantage/No Harm Sam Do not Use PED Use PED Mark Wins/Sam Loses Use PED Sam Wins/Mark Loses No Advantage/Harm