Which revision corrects Sam's error in the use of dashes to set off a clause in sentence 4? The longhorns had been skittish, but Johnny Chillers, who was named for the old Chillers trail, sang to them - whenever they started to spook - to calm them down. The longhorns had been skittish, but Johnny Chillers, who was named for the old Chillers trail, sang to them - whenever they started to spook - to calm them down. The longhorns had been skittish, but Johnny Chillers - who was named for the old Chillers trail sang to them - whenever they started to spook to calm them down. The longhorns had been skittish, but Johnny Chillers - who was named for the old Chillers trail sang to them - whenever they started to spook to calm them down. The longhorns had been skittish, but Johnny Chillers - who was named for the old Chillers trail - sang to them whenever they started to spook to calm them down. The longhorns had been skittish, but Johnny Chillers - who was named for the old Chillers trail - sang to them whenever they started to spook to calm them down. The longhorns had been skittish - but Johnny Chillers - who was named for the old Chillers trail, sang to them whenever they started to spook to