The correct answer is: B. Ribosomes.
Ribosomes are organelles that are found in the cytoplasm of cells. They are responsible for protein synthesis, which is the process of building proteins from amino acids. Proteins are essential for all living things, and they are involved in a wide variety of functions, including cell structure, metabolism, and gene expression.
The nucleus is the control center of the cell. It contains the cell’s DNA, which is the blueprint for all of the cell’s proteins. However, the nucleus does not actually synthesize proteins. Instead, it sends the information encoded in DNA to the ribosomes, which are the organelles that actually build proteins.
The cell wall is a rigid structure that surrounds the cell membrane. It is made of cellulose, a type of carbohydrate. The cell wall provides support and protection for the cell. However, it does not play a role in protein synthesis.
Therefore, the correct answer is: B. Ribosomes.