After Reading the Paragraph Below, Answer the Questions That Follow

Multiple Choice

After reading the paragraph below, answer the questions that follow.
In examining the effects of atrazine, one of the most commonly used herbicides in the world, scientists studied the mating behavior of male frogs exposed to atrazine (Atr) compared to a group that was not exposed (Non) . The results are shown in the figure.

-The role of the nontreated males in this experiment is

A) to increase the sample size.
B) to act as controls.
C) to show that not all matings are successful.
D) to determine number of matings per frog.