Which situation would pose a major difficulty for applying the biological species concept?

Option C

Explanation:

Complete Question

Which of the following situations would pose a major difficulty for applying the biological species concept?

a) Two populations of sexually reproducing plants that can be bred easily in the same location under field conditions

b) Two populations of sexually reproducing insects that can be bred easily in the same location under field conditions

c) Five snail fossils taken from the same locality during a 400,000-year time span

d) Dimorphic mating pairs of birds

e) Monomorphic mating pairs of birds

Solution -

According to the biological species concept, two or more organisms that look alike does not mean that they belong to the same species. In order to consider that two organisms belong to the same species, it is essential for them to be able to interbreed or mate.  

For example –  

Western meadowlarks and Eastern meadowlarks look identical to one another but they do not interbreed with each other and hence they belong to different species.

Hence, option C is correct

the correct answer is d