The correct option is B Chloroplasts
Chloroplasts are organelles and specialized subunits in plant and algal cells. Their main role is to conduct photosynthesis, where the photosynthetic pigment chlorophyll captures the light energy from sunlight, and converts into chemical energy. Thus, option B is correct.
Ribosomes are the protein-synthesizing machines of the cell. They translate the information encoded in messenger RNA (mRNA) into a polypeptide. Thus, option C is wrong.
Mesosomes are organelles of bacteria that appears as an invagination of the plasma membrane and functions either in DNA replication and cell division or excretion of exoenzymes. Thus, option D is incorrect.
Pyrenoids are sub-cellular micro-compartments found in chloroplasts of many algae, and in a single group of land plants, the hornworts. Pyrenoids are associated with the operation of a carbon-concentrating mechanism (CCM). Thus, option A is incorrect.