Refer to the Figure

Multiple Choice

Refer to the figure.
Vredenburg studied the impact of the introduction of rainbow and brook trout on a species of amphibian, the mountain yellow-legged frog (Rana muscosa) . After showing greatly decreased frog populations in lakes with trout, he set up an experiment using three categories of lakes: lakes from which he removed trout, lakes that had never had trout, and lakes that still contained trout. He compared the number of adult frogs per 10 m of shoreline in all groups, as shown in the figure. What is the most likely reason that Vredenburg chose to use a large-scale experimental design such as this, rather than a single lake or laboratory experiments?

A) The larger design allowed Vredenburg the ability to do replications.
B) A smaller study would not adequately answer the experimental question.
C) In a larger study, it is easier to manipulate the various experimental treatments.
D) In a real-world situation such as this, all variables can be more easily controlled.