A map titled Physical Features of East Asia. A key shows Lowlands in green, Highlands in yellow, and mountains with brown triangles. China is surrounded by the following countries: India, Pakistan, Afghanistan, Kazakhstan, Mongolia, North Korea, South Korea, Laos, Thailand, and Bangladesh. The map has labels 1 through 4. 1 is a river in Mongolia. 2 is a river in southern China. 3 is a river south of the Qin Mountains. 4 is a river north of the Qin Mountains. Which number on the map shows the Yellow River?

1
2
3
4