A particular herbivore species $\mathbf{X}$ was being studied. There are two populations of this species, one found in Sri Lanka and the other in Indian mainland. Five thousand years ago, species $\mathbf{X}$ had a variety of colours - blue, green, red and yellow. Species $\mathbf{X}$ of all the four colours were equally prevalent in both the locations. In the present-day Sri Lankan Island, while species $\mathbf{X}$ of all these colours are still found, the majority of the population is green in colour. If this change in population distribution is solely due to founder effect, the statement most likely to be true is:

• Correct answer
  A

  A severe earthquake killed a large number of species $\mathbf{X}$ of all colours, after which the individuals that came in from Indian mainland were predominantly green in colour.
• B

  The green-coloured species $\mathbf{X}$ could perfectly camouflage with the vegetation of the forest and were thus less predated upon by carnivores.
• C

  A severe earthquake killed a large number of species $\mathbf{X}$ of all colours, and survivors were green in colour merely by chance.
• D

  The number of species $\mathbf{X}$ that were green-coloured, decreased in Indian mainland due to predation.

Hence, the correct answer is option: 'A'.