The correct answer is option 2: Proteins. Mitochondria are known as the powerhouses of the cell because they are responsible for producing the majority of the cell`s energy in the form of ATP (adenosine triphosphate). While mitochondria do have their own DNA and can replicate independently of the cell`s nucleus, they are unable to produce their own nucleus. However, mitochondria do have the ability to produce their own proteins. This is because they contain their own ribosomes, which are small structures responsible for protein synthesis. These ribosomes are distinct from the ribosomes found in the cell`s cytoplasm, which are responsible for protein synthesis for the rest of the cell. The proteins produced by mitochondria are essential for the proper functioning and maintenance of these organelles. Therefore, option 2, Proteins, is the correct answer.