The correct option is D plastids
Plasma membrane is what holds all the contents of the cell together. A cell cannot survive without a cell membrane, let alone divide mitotically.
Mitochondria is the powerhouse of the cell. It is responsible for generating ATP, which are molecules that power all activities of the cell including mitosis.
Cytoskeleton is the network of protein filaments that hold the different organelles in place within the cell. It is the proteins of the cytoskeleton that help in the spindle formation during mitosis and meiosis.
Plastids are specific for plant cell and absent in animal cells. Main function of plastids is, synthesis and storage of food. Therefore mitosis will occur even in the absence of plastids. Hence, cell can function properly and divide mitotically even in the presence or absence of plastids.