On an oceanic island, long isolated away from any continent, there are only four co-existing species: flowering shrub, rabbit, large deer and small fox. The food web for the island ecosystem is depicted below.


Deer and rabbit eat precisely the same parts of the flowering shrub, depleting the shrub vegetation at precisely the same rates. If predation is NOT the reason that the four species coexist, choose the statement that best explains their coexistence.

• A

  Deer population is large in number.
• B

  The population of small fox is larger than that of rabbit.
• C

  Interspecific competition is stronger than intraspecific competition.
• Correct answer
  D

  Intraspecific competition is stronger than interspecific competition.

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