What Would You Predict About the Genes Involved in a Drug's

What would you predict about the genes involved in a drug's metabolism if you see a discontinuous dose-response curve in a population?

A) One gene is mainly responsible for the metabolism
B) The number of genes involved in the metabolism is equal to the number of peaks in the response curve
C) There are multiple genes involved in the metabolism, but this would not tell you how many
D) There is a threshold for induction of the gene involved in the metabolism
E) A dose-response curve provides no information on the genetics of drug metabolism