The fur trappers became guides for lands west of the Rockies because there were fewer animals west of the Rockies.
A trapper is an individual who hunts and traps animals. Animal fur capture takes place in almost every country in the world. Capture is primarily for animal fur, but it can also be for food. Fur can be harvested by gun or bow hunting, but most of Pelto's wildlife is harvested by traps.
Trapping is a cruel and dangerous activity that threatens wildlife, humans and livestock.
Thus, option B is true as because of a fewer animals in west of the Rockies caused the fur trappers to change their occupation as guide.
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