According the following requirements to create user, user group and the group members:
– A group named admin.
– A user named mary, and belong to admin as the secondary group.
– A user named alice, and belong to admin as the secondary group.
– A user named bobby, bobby’s login shell should be non-interactive. Bobby not belong to admin as the secondary group Mary, Alice, bobby users must be set "password" as the user’s password.
A. See explanation below.