In the Sonoran Desert of the Southwestern United States, Scientists

In the Sonoran desert of the southwestern United States, scientists observed that population clusters of a small cactus were very pronounced around nests of desert woodrats. They began to think the woodrat was somehow connected to the seeding of these cactus plants.After years of counting and observing the woodrat nests and cactus plants, they collected the droppings of the woodrats and took them back to the lab to analyze them to see if they contained seeds of the cactus. They also collected the droppings and transported them to other areas to see if this would bring about new population clusters of the cactus.They also programmed the data they had collected into a computer. The computer program allowed the scientists to predict that increases in the woodrat population would result in increases in the cactus population, and likewise a decrease in woodrats would signal an impending decrease in cactus.
-Which of the following best describes the scientists' initial observations?

A) Woodrat nests had no apparent effect on cactus populations.
B) Cactus plants were less common close to woodrat nests.
C) Cactus plants were more common close to woodrat nests.
D) Cactus plants and woodrat nests were mutually exclusive.
E) The effect of woodrats on cactus plants was different from season to season.