Plant hormones are chemical regulators that stimulate or inhibit growth depending on their concentration and type of tissue in which they are found. Based on the information in the graph, which is a correct conclusion about plant hormones?

F. They stimulate maximum root growth and stem growth at the same concentration.

G. They stimulate maximum stem growth at low concentrations.

H. They stimulate maximum root growth at high concentrations.

J. They stimulate maximum root and stem growth at different concentrations.