What is the function of the linear area of bone that is the external oblique ridge?

The external oblique ridge serves primarily as a site for muscle attachment, which is why option B is correct. This ridge is a prominent bony landmark on the mandible and provides a point of origin for muscles such as the buccinator. These muscles play significant roles in facial movement, mastication, and maintaining the shape and function of the oral cavity.

In addition to its role in muscle attachment, the external oblique ridge may also possess clinical significance during procedures like local anesthesia injections, but its primary function pertains to muscle anchorage. The other options, while relatable to aspects of dental and anatomical knowledge, do not accurately describe the main functional role of the external oblique ridge.