The command sudo sed 's/Random/Sonar/g' /root/nautilus.xml will not actually append/save the changes into target file. You should have used sed command with -i option which is used to actually insert the changes into target file.
Please go through the man pages of sed command for more details.
however, when I re-opened the file for verifying purpose, I was able to see all instances of Random updated with Sonar.
so this would have been a successful task completion?
sudo sed -i ‘s/Random/Sonar/g’ /root/nautilus.xml
As per screenshot and details you shared the command you used is sudo sed ‘s/Random/Sonar/g’ /root/nautilus.xml and it was supposed to display the expected output but it won’t save the results into target file so it was expected to fail.
You might be assigned this task again in future you so can give it a try again
I was able to complete the task using this resource.
It took me a few tries though to get the sed command to work. I was not able to cat the xml file at first or run the sed command. Strange. Maybe, I had too much coffee today.