Where does cementum attach on a tooth?

Cementum is a specialized calcified tissue that covers the roots of teeth. Its primary function is to anchor the tooth to the surrounding alveolar bone via the periodontal ligament (PDL). The attachment occurs specifically at the area where the periodontal ligament fibers connect to the cementum, which is at the root portion of the tooth. This integration is crucial for the stability of the tooth within its socket, allowing for the necessary support during chewing and other functions.

The other choices do not accurately reflect the correct location where cementum attaches. Cementum does not cover the enamel, which is found on the crown of the tooth; hence, it does not attach at that surface. Similarly, while it is present throughout the root structure, it does not exclusively attach at the apex of the root. Instead, its attachment is more extensive along the root surface where it meets the periodontal ligament, facilitating the connection necessary for dental stability.