Answer:
a, b, c, d only
Explanation:
Population is a group of organisms that belong to a single species that reside in a specific area. In the following cases where a single species name is mentioned they can be considered as population.
a. the American bison (Bison bison) and grey wolves (Canis lupus) currently living in Yellowstone National Park - populations
b. all of the rainbow trout (Oncorhynchus mykiss that) that have ever lived in Lake Erie - population
c. the group of American bison (Bison bison) currently living in Yellowstone National Park- population
d. a group of calliope hummingbirds (Selasphorus calliope) and a group of rufous hummingbirds (Selasphorus rufus) living in the same New Hampshire woods - Populations
e. the northern cardinals (Cardinalis cardinalis) living on opposite shores of Lake Champlain- Not a population as they are spread far apart from each other reducing the chances of sexual interbreeding.
f. All of the whales currently living in the Atlantic Ocean off Cape Cod, Massachusetts - Not a population as the organisms of closely related species may have been considered
