On an island, black-bellied seed cracker birds feed primarily on seeds of two species of sedge plant. These seeds are similar in size but differ dramatically in their hardness. The distribution of bill size (as measured by the width of the lower section of the bill i.e. mandible) for an adult population of these birds is represented below.


This distribution is most likely a result of:

• A

  stabilizing selection
• Correct answer
  B

  disruptive selection
• C

  directional selection
• D

  convergent evolution

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