Which of the following is the principle pigment of Phaeophyceae?
 

Phaeophyceae is a brown algae family that includes brown seaweeds. They are multicellular, macroscopic seaweeds found in marine environments, particularly temperate and cold waters.
Fucoxanthin is the primary pigment in Phaeophyceae (brown algae). Fucoxanthin is a xanthophyll pigment that gives brown algae their brown colour. It is also an important part of their photosynthetic apparatus, and it protects the algae from excessive light and UV radiation.