All the cells regardless of their sizes consists of
a) Plasma Membrane - It is a membrane that outlines distinguished boundaries between the cell component and external environment and prevents the flow of molecules.
b) A space designated to the storage of genetic material like DNA. This space is usually called nucleus in Eukaryotas but this is not present in prokaryotic cells.
c) Cytoplasm is present as a boundary that consists of semi-fluid substance this cytoplasm is absent in bacteria only.
d) Ribosomes are cell organelles that causes DNA modification and are very essential for cell life.
Thus it can be stated that it can be the cytoplasm and nucleus which may or may not be present in few cells.
So the correct answer can be A