Arsenal definitely knows if they want to be table till the end of the year they have to win this match but this does not mean West ham will be sleeping in the match. I guess we all can agree that Arsenal will win this match but I don't they will be topping the league for long, Liverpool more likely will be crown Epl champion, since City are far from their best and still continue to have injury woes
Arsenal staying at the top of the table till the end is currently not guaranteed because West Ham isn't a team that will be considered weak so they are definitely going to give Arsenal a hard time winning and then a draw wouldn't get Arsenal to the top of the table either because they are currently two points away form the top.
Arsenal winning is still a speculation, west ham most recently have been putting up a really good performance, they did suffered only one loss in their last five games and a draw aswell meanwhile the rest three games were won so it will be fair to say they aren't in a bad form and are very likely ready enough to face the gunners, they are sure going to stress the gunners a little but then if the gunners are lucky they may be having a good day and go home with three points, if it turns out west h is lucky then they will be displacing the red devils (Manchester united) .