3 persons play a game by tossing a fair coin each independently. The game ends in a trial if all of them get the same outcome in that trial,otherwise they continue to the next trial. what is the probability that the game end in an even number of trials.

options are 1)2/7 2)3/7 3) 1/2 4) 4/7

Please help me out in this ques asap.its very urgent