Choose the homologous organs from the given options.
$(I)$ Vertebrate hearts.
$(II)$ Vertebrate brains.
$(III)$ Thorn and tendrils of Bougainvillea and Cucurbita respectively.
$(IV)$ Vertebrate limbs.
The correct combination is:

• A
  $I$ and $II$ only
• B
  $II$ and $III$ only
• C
  $III$ and $IV$ only
• D
  $I, II, III$ and $IV$