What is the default permission set when a file is created in Linux?

When a file is created in Linux, the default permission set is typically 644. This means that the owner of the file has read and write permissions, while members of the group and others have read-only permissions.

This default is based on the system's umask value, which specifies a base set of permissions that will be masked (i.e., removed) from the default permissions assigned to the owner, group, and others when a new file is created. Since regular files in Linux are usually created with default permissions of 666 (which allows read and write for everyone), the umask value of 022 (which masks out the write permission for group and others) results in the file permissions being set to 644.

The rationale behind this is to ensure that files are not accidentally made writable by all users, which could lead to security risks. Therefore, option C is the correct answer, as it accurately represents the typical default permission scheme for newly created files in Linux environments.