Darling is a :

Canal
City
Lake
River

The correct answer is (d). Darling is a river in Australia. It is the longest river in New South Wales, and the second longest river in Australia, after the Murray River. The Darling River rises in the Great Dividing Range in the Snowy Mountains, and flows west and then south for 2,700 kilometers (1,680 mi) before joining the Murray River near Wentworth. The Darling River is a major source of water for irrigation and agriculture in the Murray-Darling Basin. It is also a popular destination for fishing, boating, and camping.

(a) A canal is a man-made waterway that is used for transportation or irrigation. Canals are typically much smaller than rivers, and they are often straighter.

(b) A city is a large human settlement. Cities are typically defined by their population size, density, and infrastructure.

(c) A lake is a large body of water that is surrounded by land. Lakes can be freshwater or saltwater, and they can be natural or man-made.