Which among the following is incorrect?

Q. Which among the following is incorrect?

1. Algae help in increasing oxygen levels in the environment
2. Chlorella and Spirullina are multi-cellular algae that are rich proteins and are used as food supplements for space travelers
3. Chlorophyceae comprise algae that contain chlorophyll a and chlorophyll b
4. Chlorophyceae store food as proteins, starch or as oil droplets

Answer: Chlorella and Spirullina are multi-cellular algae that are rich proteins and are used as food supplements for space travelers