The correct answer is (a) Lower Ganga Canal.
The Lower Ganga Canal is a canal system in the Indian state of Uttar Pradesh. It is the longest canal in the state, and one of the longest canals in India. The canal was built in the 18th century, and it is used for irrigation and drinking water. The canal is about 1,000 kilometers long, and it irrigates over 2 million hectares of land.
The Ghaghara Canal is a canal system in the Indian states of Uttar Pradesh and Bihar. It is a branch canal of the Gandak Canal, and it is used for irrigation and drinking water. The canal is about 500 kilometers long, and it irrigates over 1 million hectares of land.
The Sharda Canal is a canal system in the Indian states of Uttar Pradesh and Madhya Pradesh. It is a branch canal of the Yamuna Canal, and it is used for irrigation and drinking water. The canal is about 400 kilometers long, and it irrigates over 800,000 hectares of land.
The Ken Canal is a canal system in the Indian state of Madhya Pradesh. It is a branch canal of the Betwa Canal, and it is used for irrigation and drinking water. The canal is about 300 kilometers long, and it irrigates over 600,000 hectares of land.