The correct answer is “b” (Lysosomes)
One of the most important functions of lysosomes is “Organelle turnover.” If extra organelles are there in a cell, then these would be useless for the cell; because the cell’s physiology cannot support this many organelles, for e.g. excess of mitochondria, Golgi bodies, ribosomes etc. In such a situation, the lysosomes, engulf these extra, useless organelles. This phenomenon is a part of “autophagy”; and results in “Organelle turnover”, i.e. maintaining the exact number of each and every organelle inside a cell.