Update List of Available Packages

A

The correct answer is A. apt-get update.

Explanation:

The dpkg based package management system is a low-level tool for installing, configuring, and removing software packages in Linux distributions. In dpkg, packages are installed and managed individually, without any dependency checking or automatic updates.

To update the list of available packages in the dpkg system, you need to use a higher-level tool that can handle package repositories, dependencies, and version management. One such tool is apt-get, which stands for Advanced Package Tool.

The apt-get command has several sub-commands, including update, upgrade, install, remove, and more. The update sub-command is used to update the package lists from the configured repositories. This means that apt-get will fetch the latest information about the available packages, their versions, dependencies, and other metadata, and store them in the local cache.

The syntax for apt-get update is:

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sudo apt-get update 

The sudo command is used to run apt-get as a superuser, which is required for updating the system-wide package lists. If you don't use sudo, you may get a permission denied error.

Once you run apt-get update, you should see output similar to this:

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Get:1 http://archive.ubuntu.com/ubuntu bionic InRelease [242 kB] Hit:2 http://security.ubuntu.com/ubuntu bionic-security InRelease Get:3 http://archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB] ... 

This output shows that apt-get is fetching the package lists from the Ubuntu repositories (in this case, for the Bionic version), and displaying the progress and status of the downloads.

After apt-get update, you can use other apt-get sub-commands to install or upgrade specific packages, based on the updated package lists.

To summarize, apt-get update is the command used to update the list of available packages when using dpkg based package management. It fetches the latest package metadata from the configured repositories and stores it in the local cache. This enables you to use other apt-get sub-commands to install, upgrade, or remove packages with the latest versions and dependencies.