Many of the bones from the prehistoric Cowboy Wash site in Colorado show evidence of cannibalism. Dr. Larsen suggests that environmental stresses may have led to a reduction in agricultural yields, causing a surge in interpersonal conflict over land. This is certainly not the only explanation for cannibalism, however, because
a. eating meat was necessary for human evolution, and eating human meat sped up the process.
b. cannibalism is a modern phenomenon engaged in by psychopaths.
c. evidence of cannibalism is found long before the advent of agriculture.
d. All of the above