The longest river of China is :

Yangtze (Yang Tse Kiang)
Hwang Ho
Wei Ho
Si Kiang

The correct answer is (a) Yangtze (Yang Tse Kiang).

The Yangtze River is the longest river in Asia and the third longest river in the world, after the Nile River in Africa and the Amazon River in South America. It flows through 11 provinces and municipalities in China, and its drainage basin covers about 2.7 million square kilometers (1.05 million square miles). The Yangtze River is a major source of water for irrigation, drinking water, and hydroelectric power in China. It is also a major transportation route, and its delta is one of the most densely populated areas in the world.

The Hwang Ho, also known as the Yellow River, is the second longest river in China. It flows through nine provinces in China, and its drainage basin covers about 750,000 square kilometers (290,000 square miles). The Hwang Ho is known for its frequent flooding, which has caused extensive damage over the centuries.

The Wei Ho is a river in northern China. It flows through the provinces of Henan and Shaanxi, and its drainage basin covers about 120,000 square kilometers (46,000 square miles). The Wei Ho is a major tributary of the Yellow River.

The Si Kiang, also known as the Pearl River, is the third longest river in China. It flows through the provinces of Guangdong, Guangxi, and Yunnan, and its drainage basin covers about 450,000 square kilometers (174,000 square miles). The Si Kiang is a major transportation route and a source of water for irrigation and drinking water in southern China.