The command 'apt-get install namepackage' is used to install a package specified by 'namepackage' on Ubuntu, which is a Debian-based Linux distribution. It does not remove, update, or list packages.
The command apt-get install namepackage in Ubuntu is used to install a package. When you execute this command, the Advanced Packaging Tool (APT) system searches the repositories listed in your system's sources list, downloads the specified package along with any necessary dependencies, and installs them on your system. This is a fundamental command for managing software on Ubuntu and other Debian-based Linux distributions.
As for the options provided in the question, the correct answer is B) Installs a package. This command doesn't remove, update all packages, or list installed packages, which are different operations with respective commands like apt-get remove, apt-get update, and apt list --installed.