B. It has a whip, like a tail
Explanation - Protists are unicellular organisms. Some multi-cellular organism might exist. Some protists have silica plated scales on their body surface like diatomaceous earth. They exhibit both type of respiration - aerobic and anaerobic. They mainly have parasitic mode of nutrition.
Protists also have flagella which they whip that in turn helps in their movement and this feature have made them to enter into the water body, example - euglena. Paramoecium have cilia on their entire surface that helps in their locomotion in water.