'Operation Flood' scheme was operated by

Answer: Option A

The correct answer is Option A: NDDB, Anand.

Operation Flood, also known as the White Revolution, was a large-scale dairy development program in India.
Its main goal was to increase milk production and make India self-sufficient in milk.

The National Dairy Development Board (NDDB), located in Anand, Gujarat, was the key organization responsible for planning, implementing, and managing Operation Flood.

Now, let's look at the other options:

NDRI, Karnal (National Dairy Research Institute) is an important research institution for dairy science, but it wasn't the main operational body for Operation Flood.
IVRI, Izzatnagar (Indian Veterinary Research Institute) focuses on veterinary research, not primarily dairy development.
NDRI, Bengaluru (National Dairy Research Institute) is another campus of the National Dairy Research Institute but NDDB, Anand was the main body.

Therefore, NDDB in Anand was the central agency that drove the success of Operation Flood.