Plant Hormones Can Have Different Effects at Different Concentrations

Plant hormones can have different effects at different concentrations. This explains how ________.

A) some plants are long-day plants, while others are short-day plants
B) signal transduction pathways in plants differ from those in animals
C) plant genes recognize pathogen genes, although plants lack an immune system
D) auxin can stimulate cell elongation in apical meristems yet inhibit the growth of axillary buds
E) gibberellin concentration can both induce and break seed dormancy