Which Statement About Patterson's Study of the Distributions of Tamias

Which statement about Patterson's study of the distributions of Tamias chipmunks in the southwestern United States is false?

A) It found that in mountain ranges where two species were present, the overlap of their distributions was small.
B) It found that in mountain ranges where only one species was present, that species was found over a broader distribution of habitats than would have been possible in the presence of a competitor.
C) They were manipulative experiments.
D) They suggested that competition is limiting the ranges of the species.