Question: Which city was formerly of Shazhou County, Gao'an or Zhangjiagang?
Related documents: [0]  [DOC] Gao'an () is a city in the province of Jiangxi, China. It is a county-level city, under the jurisdiction of the prefecture-level city of Yichun. [END] 
[1]  [DOC] Zhangjiagang (), formerly Shazhou County (沙洲县), is a county-level city under the administration of Suzhou, Jiangsu province, China. With 1,246,762 inhabitants at the 2010 census, the city is now part of Jiangyn-Zhangjiagang-Jingjiang metropolitan area with 3,526,260 inhabitants. Continued growth will encompass the Shanghai-Suzhou-Wuxi-Changzhou Metroplex. It borders the prefecture-level cities of Taizhou and Nantong across the Yangtze River, as well as Wuxi to the west. [END] 
Answer: 
Zhangjiagang
Zhangjiagang