The correct option is B Pyrenoids
Pyrenoids are sub-cellular micro-compartments found in chloroplasts of many algae, and in a single group of land plants, the hornworts. These store starch and proteins.
Leucoplasts are non-pigmented plastids known to store starch, oils, fats and proteins.
Mesosomes are infoldings of prokaryotic cell membranes. They They are involved in cell wall formation, DNA replication, respiration, secretion processes, etc.
Fronds refer to the leaves of Pteridophytes.