The Incorrect Statement:

The incorrect statement regarding FTP is option 'C' - "FTP sends its control information in-band."

Explanation:

FTP (File Transfer Protocol) is a standard network protocol used for transferring files between a client and a server over a TCP/IP network. It operates on the application layer of the TCP/IP protocol suite.

1. FTP Stands for File Transfer Protocol:

FTP stands for File Transfer Protocol. It is a standard network protocol used for transferring files from one host to another over a TCP/IP-based network.

2. FTP Uses Two Parallel TCP Connections:

FTP uses two parallel TCP connections during its operation. One connection is used for control information and the other for data transfer. The control connection is established between the FTP client and the FTP server on Port 21. It is responsible for sending commands and receiving responses regarding the file transfer. The data connection is established dynamically and used for transferring the actual data files.

3. FTP Sends Its Control Information Out-of-Band:

Contrary to the statement in option 'C', FTP sends its control information out-of-band. The control information includes commands like login, password, directory navigation, file transfer commands, etc. It is sent separately from the data connection and doesn't interfere with the actual file transfer. The control information is transmitted over the control connection established on Port 21.

4. FTP Can Send Multiple Files Over the Data Connection:

FTP is capable of sending multiple files over the data connection. It supports various commands to handle multiple files, such as sending multiple files in a batch, retrieving multiple files, deleting multiple files, etc. The data connection is used to transfer the files between the client and server.

Conclusion:

In summary, the incorrect statement regarding FTP is that it sends its control information in-band. The control information is sent out-of-band over a separate control connection, while the data connection is used to transfer the actual files. FTP can transfer multiple files over the data connection, making it a versatile protocol for file transfer over networks.