Cedric, a software support executive at Panacx Tech. Inc., was instructed to install the Ubuntu operating system on the computers in the organization. After installing the OS, he discovered that many unnecessary services and packages had been installed automatically without his knowledge. Because these services or packages could be harmful and pose various security threats to the host machine, he was told to disable all unwanted services.

Which of the following commands should Cedric use to stop or disable these unnecessary services or packages on Ubuntu distributions?