Answer:
The correct identification would be:
Label A- DNA
Label B- cell membrane or plasma membrane
Label C- Ribosome
Label D- Cytoplasm
The above mentioned four structures that are common to all the cells present in an environment.
DNA genetic material is present in all the cells. It is present in nucleus in eukaryotic cells and in nucleoid region in prokaryotic cells.
Plasma membrane is a semi-permeable membrane present around all the living cells.
Similarly, cytoplasm refers to jelly like substance present in all the cells. It supports cell organelles.
Ribosomes form the site for protein synthesis in all the living cells.