Which of these are valid TFTP error codes? (Choose two.)

TFTP (Trivial File Transfer Protocol) uses a simple set of error codes. Error Code 1, "File not found," is a common response when a client requests a file that does not exist on the TFTP server. Error Code 6, "File already exists," occurs during a write operation (upload) if the server is configured not to overwrite existing files and the client attempts to upload a file with a name that already exists. "Unknown error" (Error Code 2) is a valid TFTP error, but it was not one of the selected correct options. "Invalid user" (Error Code 3) and "Undefined error" (Error Code 8) are not standard TFTP error codes. TFTP's simplicity means it has a limited set of defined error conditions.