The correct option is B They perform oxygenic photosynthesis
Heterocysts are hyaline cells which help in nitrogen fixation and help in fragmentation. They do not help in sexual reproduction in Cyanobacteria.
The cyanobacteria lack chlorophyll b. In addition, they have phycocyanin and phycoerythrin pigments.
Cyanobacteria perform oxygenic photosynthesis which means that during photosynthesis, oxygen is released as a byproduct.
The common reserve food material in cyanobacteria is cyanophycean starch. Other inclusions include lipid droplets, volutin granules(polyphosphate), etc.