What Can Be Inferred from the Graph Below

Multiple Choice

What can be inferred from the graph below?

A) The biological response for both toxicants increases as the dose is increased.
B) For both toxicants, a harmful response occurs only above a certain threshold level, that is different for each toxicant.
C) Toxicant A has a lower effective dose-50 percent (ED₅₀) than toxicant B.
D) All of the above can be inferred from the graph.