The correct option is C Idioblast
The waste products are stored in a parenchymatous cell known as an idioblast. An idioblast is an isolated plant cell that differs from neighbouring tissues. The functions of an idioblast are storage of reserves, excretory materials, pigments, and minerals. They could contain oil, latex, gum, resin, tannin or pigments etc. Some can contain mineral crystals such as acrid tasting and poisonous calcium oxalate or carbonate or silica. Any of the tissue or tissue systems of plants can contain idioblasts.
Thus, the correct answer is option C.