Kyle and Stan Are Playing Odds or Evens, Where Kyle

Kyle and Stan are playing Odds or Evens, where Kyle is designated as the "odd"player and Stan is designated as the "even"player. They decide to play the game 10 times. If Kyle plays his ideal mixture, Stan's expected payoff is zero when he

A) plays a pure strategy of "shoot 1."
B) plays a pure strategy of "shoot 2."
C) plays his ideal strategy.
D) All of the above are correct.