in game theory a dynamic game in extensive form has two players which are player one and player two

player one have left and right - if player one chooses left player 2 have A and B
if one chooses right player two have C and D then if player two chooses C player one have E and F - on the other hand if player two choose D player one have G and H - the question is identify the strategy set for both players (i.e. the available strategies for each player) now i get confused between this and strategy combinations so how can i solve this question?HELP! final in couple of days!