Arsenal just won their last game in FA Cup, thereby boosting their morale. Now they have to go all out in Premier League if they want to take part in Champions League football next season. Besides, their home strength has been solid.
On the other hand, West Ham have been terrible on away soil lately.
The AH line is home team (-1.00), which is in favor of Arsenal.
Therefore the Gunners should be able to win this home game.