I believe it would be magnet number four, this is because, with magnets, not people, opposites attract. Magnet 4 is the closest magnet to the large magnet with it's opposite facing the large magnet.
The magnet the will experience the strongest pull will be Magnet 4 because opposite ends of magnets attract and since Magnet 4 is the closest one to the main magnet it will have the strongest attraction.
Magnets 2 and 3 will not work because they have the same poles pointing toward each other.
