Concept:The outermost layer of a tooth is the hardest and protects the inner parts.
Explanation:The tooth has multiple layers, each with a different function.
Enamel is the hard, outermost surface of the crown of a tooth.
It is the hardest tissue in the human body and protects the tooth from wear and bacteria.
Dentine lies just beneath the enamel and is softer than enamel.
Cement covers the root of the tooth, helping anchor it in the jawbone.
The root is the part embedded in the bone, not the outer surface.
Answer:D. Enamel