The correct answer is option 2, Lake Victoria.

The River Nile is one of the world`s longest rivers, spanning multiple countries in Africa. It has two main tributaries: the White Nile and the Blue Nile. The source of the White Nile, which contributes about 15% of the river`s flow, is Lake Victoria. Lake Victoria is located in East Africa and is the largest lake in Africa by surface area. It is fed by various rivers, rainfall, and groundwater. From Lake Victoria, the White Nile flows northward to join the Blue Nile in Sudan, forming the Nile River. While Lake Tanganyika is also a large lake in Africa, it is not the source of the River Nile. Similarly, Lake Chad and Lake Nassir are not the sources of the Nile.