Final answer:
The correct term for the line where the alveolar membranes meet with the attached gingiva is the Mucogingival Junction.
Step-by-step explanation:
The term that defines the line in the oral tissue where the alveolar membranes meet with the attached gingiva is B) Mucogingival Junction. The anatomy of a tooth involves the alveolar processes, which are part of the maxilla (upper jaw) or mandible (lower jaw), and serve as sockets to secure the teeth. The gingivae, or gums, are the soft tissues lining these processes and surrounding the teeth.
The mucogingival junction represents the boundary where the attached gingiva, a firmer and more resilient area of gum, meets with the alveolar mucosa, which is looser and more flexible. This junction is clinically important because it marks the transition between the firmer tissue that is attached to the bone and the looser tissue that begins the movable part of the mouth floor.