【单选题】

What is the role of pheromones ill the mass migrations of ants
A．(Pheromones are used to create a trail that directs the ants during migrations

B．( Pheromones signal the ants that the nest has been invaded and must be abandoned
C．( Pheromones control the speed at which ants move from one location to another
D．( Pheromones enable scouts to identify suitable areas for establishing a new nest