There are some growers that like to leave multiple sprouts on a plant, as the number of flowers will be increased. However, they often report much smaller bloom size and crowded conditions. For some, that is just fine.

All the serious growers I know only allow one or two sprouts to develop, and 'stop' the plant at 3-6 leaf sets to encourage each sprout to branch out instead of grow up. Limiting each tuber to one sprout, stopping early and disbudding severely maximizes the potential of each bloom. Some of the giant varieties are allowed only 3-4 blooms for the whole season in order to get that one perfect show bloom.

Bottom line- how many sprouts you leave on the tuber depends on your goals for that plant. I would suggest nipping off four as close to the tuber as possible, and sticking them in the ground with only their top sprout is peeking out, away from the tuber about 8 inches. They have a chance at rooting with no extra attention from you, and if they die you don't have an empty space. If even one roots, you'll have an extra plant that will bloom a bit later then the tuber plant, with tubers that can be dug up for next year.