Final answer:
Fibrocartilage is the correct answer, as it is the structural intermediate between hyaline cartilage and dense regular connective tissue due to its combination of flexibility and strength.
Step-by-step explanation:
The cartilage that serves as a structural intermediate between hyaline cartilage and dense regular connective tissue is fibrocartilage. Hyaline cartilage is common throughout the body, particularly at joint surfaces, and is characterized by its smooth, clear appearance and flexibility. It contains short, dispersed collagen fibers. In contrast, fibrocartilage contains thick bundles of collagen fibers, making it exceptionally tough and suited for areas in the body that withstand pressure and tension, such as the menisci in the knee and the intervertebral discs. Elastic cartilage, while not the correct answer to the question, offers firm but elastic support and contains both collagen and elastic fibers; it is found in structures such as the ear and the larynx.