The correct answer is option 4, Fisheries. The term "Blue Revolution" is used to describe the growth and development of the fisheries sector. It refers to the transformation and modernization of the fisheries industry to increase the production of fish and other seafood. This includes the implementation of new technologies, improved infrastructure, and sustainable fishing practices. The Blue Revolution aims to meet the growing demand for fish and contribute to food security, employment generation, and economic growth. Option 1, Space research, is incorrect as it is unrelated to the Blue Revolution. Option 2, Poultry, and option 3, Drinking water, are also incorrect as they are not directly associated with the concept of the Blue Revolution.