Which of the following pigments are not present in Dinoflagellates?

The correct option is Chlorophyll b.

Dinoflagellates are a diverse group of unicellular, mostly marine eukaryotic algae. Like all photosynthetic organisms, they contain specific combinations of photosynthetic pigments that capture light energy for photosynthesis.

Photosynthetic dinoflagellates typically possess the following pigments:
1. Chlorophyll a and Chlorophyll c: These serve as the primary and accessory light-harvesting green pigments.
2. Carotenoids such as Fucoxanthin, peridinin, and diadinoxanthin: These accessory pigments give dinoflagellates their characteristic golden-brown or red color.

Chlorophyll b is primarily found in green algae (Chlorophyta), euglenids, and land plants. It is absent in dinoflagellates. Therefore, Chlorophyll b is not present in dinoflagellates.