The correct answer is 'Change the file permissions to allow write access for the user'. Since the user already has read access and only needs write access, modifying the file permissions using the chmod command is the most straightforward approach. The other options do not directly address the specific issue at hand. Changing the file ownership with chown is unnecessary and potentially risky if the user already owns the file. Editing the /etc/fstab file would typically configure file system mount options, not individual file permissions. Restarting the file service is unrelated to file permissions, and would not remedy the user's inability to write to the file.