In $Acacia$ species,the first few leaves are pinnately compound. Then there are leaves with flattened petiole and fewer pinnae. The leaves of the adult plant have parallel-veined flattened petioles and no pinnae. It shows that:

• A
  Leaves of the adult plant are reduced to phyllodes,while those of the seedling are unreduced.
• B
  The parallel-veined green structures of the adult plant are phylloclades.
• C
  The plant shows developmental heterophylly,compound in the seedling and simple in the adult plant.
• D
  The leaves of the adult plant are unreduced,while they are reduced in the seedling stage.