The correct answer is (d), Salween.
The Salween is a river in Southeast Asia that flows from China to Myanmar, Thailand, and Laos. It is the longest river in Southeast Asia that does not flow into the Pacific Ocean. The Salween is a major source of water for irrigation and hydroelectric power. It is also a popular destination for rafting and kayaking.
The Amur is a river in Northeast Asia that flows from Russia to China. It is the longest river in both countries. The Amur is a major source of water for irrigation and hydroelectric power. It is also a popular destination for fishing and boating.
The Lena is a river in Siberia that flows from Russia. It is the longest river in Russia and the 10th longest river in the world. The Lena is a major source of water for irrigation and hydroelectric power. It is also a popular destination for fishing and boating.
The Ob is a river in Siberia that flows from Russia. It is the longest river in Western Siberia and the 7th longest river in the world. The Ob is a major source of water for irrigation and hydroelectric power. It is also a popular destination for fishing and boating.