To copy one file from the remote machine to the local machine, the correct parameter is "GET".
Let's go through each option to understand why it is correct or incorrect:
Option A) OPEN - The "OPEN" parameter is not used for copying files from a remote machine to the local machine. It is used to establish a connection to a remote machine or open a file.
Option B) RMDIR - The "RMDIR" parameter is used to remove a directory on the remote machine. It is not used for copying files.
Option C) OUT - The "OUT" parameter is used to redirect the output of a command to a file or a device. It is not used for copying files from a remote machine to the local machine.
Option D) GET - The "GET" parameter is used to retrieve a file from a remote machine and copy it to the local machine. This is the correct parameter for copying files from the remote machine to the local machine.
The correct answer is option D. This option is correct because the "GET" parameter is used to copy one file from the remote machine to the local machine.