Which configuration file would be edited to change the default options for outbound SSH sessions?

/etc/ssh/sshd_config is the configuration file for the SSH daemon (server), not the client, and dictates how the server accepts incoming connections.

/etc/ssh/ssh is not a standard configuration file for SSH; `ssh` is the executable program itself.

/etc/ssh/client is not a standard or recognized SSH client configuration file path.

The `/etc/ssh/ssh_config` file contains system-wide default configuration for the SSH client. Options defined here apply to all users and all outbound SSH connections unless overridden by user-specific `~/.ssh/config` or command-line arguments, making it the correct file for changing default outbound SSH session options.

/etc/ssh/ssh_client is not a standard or recognized SSH client configuration file path; `ssh_config` is the correct name.