Question

what is citizen science? science projects in which the public participates by collecting data, analyzing data, or participating as subjects science projects in which scientists study citizens science projects in which citizens are trained to become scientists in the future science projects in which scientists study the nature of being a good citizen

Explanation:

Citizen science involves public participation in data - collection, analysis, or as subjects. The second option (scientists study citizens) is too broad and not the essence. The third option (training citizens to be scientists) is not the main idea. The fourth option (studying good citizenship nature) is off - topic.

Answer:

science projects in which the public participates by collecting data, analyzing data, or participating as subjects