You are the network administrator for your company. The network consists of a single Active Directory domain. All client computers run Windows XP Professional. The company has a large number of sales representatives who need access to the company network when they travel. A Windows 2000 Server computer is configured to allow users to access the network by using a dial-up connection. Several of the sales representatives occasionally travel to rural locations that have telephone lines that use outdated technology. The sales representatives report that when they attempt to establish a dial-up connection in these locations, they receive the following error message: "The server is not responding." They cannot connect to the remote access server or to the company network. Users who travel to urban areas do not report this problem. You investigate and find out that the server is running properly, but the problem persists. The sales representatives need to be able to use the dial-up connection to access the company network. What should you do?（）

• A、Change the flow control option in the modem properties to Xon / Xoff.
• B、Disable error correction in the modem's default data connection preferences.
• C、Adjust the modem's default connection speed to a lower rate. 
• D、Disable the first-in, first-out (FIFO) receive and transmit buffers on the modem.