单选题 From the passage, we know ______.

A、 Panama was ruled by three countries for 400 years
B、 The United States controlled the Panama Canal for 22 years
C、 The Panama Canal means a great deal to Panama's economy
D、 Panama is the smallest county in Central America

【正确答案】 C

【答案解析】[分析] A错在不到400年；B和、D均没有在文章中提到；文章最后一段第一句话和选项C相符。故本题答案为C。