There are 3 outcomes in each game.
For 1st game, there can be either win (W), lose(L) or Tie (T).
For each of these outcome, there can be 3 possible outcomes in 2nd game i.e. either W, L or T
So, the tree diagram will have 3 branches, each further dividing into 3 more branches(nodes)
Thus option C gives the correct tree diagram.