Which file contains group account information in Linux?

The file that contains group account information in Linux is /etc/group. This file is specifically designed to store details about user groups, such as group names, their corresponding group IDs (GIDs), and the members belonging to each group. Each line in the /etc/group file typically has the format:

group_name:password:GID:user_list

Where `group_name` is the name of the group, `password` is a placeholder (usually not used), `GID` is the numeric identifier for the group, and `user_list` includes the usernames of the members who are part of that group.

Understanding the role of this file is essential when managing user permissions and access in a Linux environment. The other files mentioned have different purposes: /etc/passwd stores user account information, /etc/shadow contains encrypted passwords and related security information, while /etc/sudoers defines user privileges for the sudo command. Therefore, the /etc/group file is the correct answer for identifying where group account information is held in Linux.