Explanation:

The Congo River, formerly known as the Zaire River is the second longest river in Africa, shorter only than the Nile, as well as the second largest river in the world by discharge volume, following only the Amazon. It is also the world's deepest recorded river, with measured depths in excess of 220 m (720 ft).The Congo-Lualaba-Chambeshi River system has an overall length of 4,700 km (2,920 mi), which makes it the world's ninth-longest river. It is the only major river to cross the equator twice. Hence option 3rd is correct.