The decimation of the buffalo could be attributed to:
a. social class envy by the Plains Indians.
b. the Bureau of Tobacco and Firearms, a paragon for notoriety, which actually condoned and
encouraged the killings with the Remington rifle.
c. the reckless slaughtering by white Anglos at a rapid rate due to large bands of whites who used
them for food and supplies, especially after the Civil War.
d. women seeking suffrage at the expense of ritual buffalo sacrifices.

C

Explanation:

Due to the abundance of the Buffalo and the major resources gained from killing them ( Meat, Fur, Horns, Bones, etc) it was natural to use them as so even with dwindling numbers. As for after the Civil War, there was a need of a potent resource during reconscrution and exploring more land, ie Buffalo.

the answer to fill in the blank in this question would be the word resource, it is defined as the money, material or people (since human resource is a very valuable good) that a company or a person has at disposition (meaning they can use the resource as they see fit), to be able to complete a task or achieve a goal.  

a. the astrolabe could determine the correct latitudinal location of the ship