People recovering from prolonged illness are often advised to include the algae Spirulina in their diet because it
Some nutrition practitioners say that blue green algae helps satisfy appetite and supplies good nutrition while dieting. Blue-green algae Spirulina, a well-known example, is a group of 1,500 species of cyanobacteria. The two most common species used for human consumption are Spirulina maxima and Spirulina platensis. Spirulina is particularly rich in protein and also contains carotenoids, vitamins, minerals, and essential fatty acids. Blue-green algae (Spirulina) is a concentrated source of nutrients compared to most foods and hence is often advised for people recovering from prolonged illness.
So, the correct answer is 'Is rich in proteins'