Answer: Option C.
Based on the color of their photosynthetic pigment.
Explanation:
Algae are simple aquatic plants without flowers that can perform photosynthesis.
They are classified based on the color of the photosynthetic pigment into three groups.
Chlorophyceae: chlorophyii Sand B are present in this group and they are also called blue green algae.
Phaeophyceae: chlorophyii A,B and fuxoxanthin are available in it. The fuxoxanthin bring about brown color in them and they are called brown algae.
Rodophyceae: chlorophyii Sand D and phycoerthrin. Phycoerthrin bring about red color and they are called red algae.
