A Designed Experiment Is Described

Multiple Choice

A designed experiment is described. Identify the specified element of the experiment.
-A herpetologist performed a study on the effects of the body type and mating call of the male bullfrog as signals of quality to mates. Four life-sized dummies of male bullfrogs and two sound Recordings provided a tool for testing female response to the unfamiliar frogs whose bodies varied By size (large or small) and color (dark or light) and whose mating calls varied by pitch (high, Normal, or low) . The female bullfrogs were observed to see whether they approached each of the Four life-sized dummies. Identify the experimental units.

A) The scientist
B) The female bullfrogs
C) The male bullfrogs
D) All of the frogs, male and female