The map shows the states that were at war in China in 260 BCE. A map titled Warring States in 260 B C E. Beginning in the north moving clockwise the states are: Yan, Qi, Chu, Qin, and Zhou. Wei and Han are in the middle. The Yellow River is west of Qin, traveling north. The Yellow River turns east then south through Zhou and Wei, continuing east and north through Qi ending at the Yellow Sea. The Yangtze River travels near the southern borders of Qin and Chu ending at the East China Sea. The map shows the states that were at war in China in 221 BCE. A map titled The Warring States in 221 B C E. Beginning in the north moving clockwise the states are: Yan, Qi, Chu, Qin, and Zhou. Wei and Han are in the middle. Qin is the largest state extending from the Yangtze River north to the northernmost point of the Yellow River. The Yellow River Is west of Qin, traveling north, turns east and continues north through Qin, Wei, Qi, ending at the Yellow Sea. The Yangtze River travels east across the bottom third of Qin, the middle of Chu, ending at the East China Sea. Compare the two maps. What advantage did northern expansion give the Qin?
control of the Yangtze River
control of the Yellow River
control of the East China Sea
control of the Yellow Sea