The correct answer is option 1, fish production. The term "Blue Revolution" is a term used to describe the significant increase and improvement in fish production and aquaculture. This revolution aims to address the growing demand for fish, to meet nutritional needs and to boost economic growth in the fisheries sector.

Option 2, milk production, is not related to the Blue Revolution. The term used to describe the significant increase and improvement in milk production is the "White Revolution" or "Operation Flood." This revolution focused on increasing milk production through various initiatives and advancements in the dairy industry.

Option 3, oil production, is not related to the Blue Revolution. Oil production is a separate industry and not directly connected to the revolution in fish production.

Option 4, food production, is a broad term that encompasses various sectors and is not specific to the Blue Revolution. The Blue Revolution specifically targets fish production and aquaculture.