The correct option is A Nucleus
Deoxyribonucleic acid (DNA) encodes the genetic instructions, which are used in development and functioning of all living organisms. Each DNA strand is made of a basic unit of one nitrogenous base + phosphate group + sugar molecule. It is situated in nucleus.
Mitochondria produces the energy currency, i.e., ATPs of the cell. Mitochondria take nutrients and convert them into energy molecules. This process is known as 'oxidative phosphorylation'.
Cell membrane is the outer covering of the cell, which protect the cell. It also supports the framework of the cell.
Nucleus of the cell contains majority of the cell's genetic material, i.e., DNA in the form of DNA-protein complex, called as chromatin.