The correct option is C Spines of prickly pear
In xerophytic plants like prickly pear or Opuntia, the leaves are modified into spines and the stem is modified as a flat, green fleshy structure called cladode for storing water.
Rhizome and corms are underground stem modifications for storing food.
A stolon is an aerial stem modification growing slightly above the soil suface giving rise to roots at the nodal regions.