The correct answer is Option 1: Acellular afibrillar cementum.

Cementum is a specialized calcified tissue covering the roots of teeth and plays a vital role in anchoring the periodontal ligament fibers to the tooth. There are different types of cementum classified based on cellular content and fiber composition:

- Acellular afibrillar cementum: This variety lacks cells (hence "acellular") and intrinsic fibers (afibrillar). It is the most basic form of cementum and usually found near the cervical region of the tooth root. It serves primarily as a protective covering and does not contribute to repair.
- Cellular intrinsic fiber cementum: Contains cells called cementocytes embedded within the matrix and primarily contains intrinsic fibers produced by cementoblasts. It contributes to repair and adaptive remodeling.
- Cellular mixed stratified cementum: Contains both intrinsic and extrinsic fibers and is cellular. This type is involved in adaptation and repair in response to functional demands.
- Cellular extrinsic fiber cementum: Contains cells and extrinsic fibers (principal fibers from the periodontal ligament). It mainly functions to anchor the tooth firmly by inserting these fibers into the cementum.

Reference: Ten Cate’s Oral Histology, 8th Edition, Chapter 7: Cementum, Page 120