Final answer:
The bone of the hard palate that exhibits prominent transverse folds is the palatine bone. These transverse folds, also known as rugae, aid in swallowing and speech.
Step-by-step explanation:
The correct answer is a. lingual.
The bone of the hard palate that exhibits prominent transverse folds is the palatine bone. The palatine bone is one of a pair of irregularly shaped bones that contribute small areas to the lateral walls of the nasal cavity and the medial wall of each orbit. The largest region of each of the palatine bone is the horizontal plate, which joins together at the midline to form the posterior quarter of the hard palate. These transverse folds are also known as rugae and they help in swallowing and speech.