Thanks for the question! So let’s take a look at rules 4 and 5. Those give us conditions for what happens when M plays tennis, and what happens when M plays golf. And we know that one of those has to be true, since M has to play one of the two sports.
So let’s say M plays tennis. Well, then S plays tennis, and S is lower than O but higher than M. Which means M is a lower rank than S, so S can’t be the lowest-ranking tennis player if M plays tennis.
OK, then let’s say M plays golf and see if S can be the lowest-ranking tennis player then. Well, if M plays golf, then S also plays golf. And each person only plays one of the two sports. So S can’t be the lowest-ranking tennis player, since S isn’t even a tennis player! So either way, it’s impossible for S to be the lowest-ranking tennis player, and Shigeru is the correct answer for this question.
Hope this helps! Feel free to ask any other questions that you might have.
