单选题 You download a file from an FTP site on the Internet. What is the highest layer in the OSI model used in this FTP operation?A. ApplicationB. PresentationC. SessionD. TransportE. InternetF. Data LinkG. Physical
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【正确答案】 1、正确答案：A    
【答案解析】解析：Explanation: Layer 7 is the application layer, which is the highest layer in the OSI model. This layer describes the use of end user applications, such as opening movie files (avi, mpeg, etc) used Microsoft Office applications, using WWW browsers, using Telnet, and using FTP.