Which environment variable is checked to determine the location of the Ansible settings file?

The variable ANSIBLE_CONFIG is used to determine the location of the Ansible setting file named ansible.cfg. The variable ANSIBLE_SETTINGS is not used with Ansible and therefore option A is an invalid answer. The ansible_connection variable is used inside of the Inventory file to explain to Ansible how to connect to a remote system. The file /etc/ansible/hosts is not a variable; it specifies the various target nodes, also called the Inventory.