Final answer:
The periodontal ligament is responsible for anchoring the tooth in its socket, and works in conjunction with the cementum that covers the tooth's root. Therefore correct option is A
Step-by-step explanation:
The part of a tooth that anchors it in its socket is the periodontal ligament. The tooth consists of a visible crown covered by enamel and a root that holds the pulp canal or root canal. The cementum covers the root and works with the periodontal ligament to secure the tooth in the jaw bone. The gums, or gingiva, surround the necks of the teeth, while the roots are embedded in the alveolar processes of the maxilla and mandible.