As americans moved west, they built the railroad and then many new towns and cities. also, as americans moved west, the buffalo population declined. why? a) trains killed many of the buffalo. b) the buffalo moved further west to survive. c) there was less grass for the buffalo to eat. d) climate change caused the buffalo to become extinct.

I would say both A or B trains split up herds and it also caused them to move further away so loss of habitat etc.  the overall cause of their decline was that why were hunted for sport but that’s not an option  

the answer is c) There was less grass for the buffalo to eat.

Explanation:

i just the usa test prep

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.