Answer:
B - Prokaryotes are the most important photosynthesizers.
Explanation:
There are some phototrophic prokaryotic organisms such as cyanobacteria and photosynthetic bacteria that carry out photosynthesis through chlorophyll-like pigments (bacteriochlorophylls) that enable them to absorb light and by using water as an electron donor in a similar way to plants. These organisms contain specialized plasma membranes which contain these photosynthetic pigments. Nonetheless, it is important to highlight that algae are the most important photosynthetic organisms in aquatic environments, while plants are the most important photosynthesizers in terrestrial environments.