Final answer:
A specialist focused on the study of the larynx, also known as the voice box, is referred to as a laryngologist. The option (a) is correct.
Step-by-step explanation:
A specialist in the study of the larynx, which is the organ of the respiratory system located between the pharynx and trachea and often referred to as the voice box due to its role in vocal sound production, is known as a laryngologist.
While a pharyngologist would specialize in the pharynx, and an otolaryngologist specializes in both the ear and throat, it's the laryngologist who is specifically focused on conditions related to the larynx. A pulmonologist, on the other hand, is a specialist dealing with the lungs and other parts of the respiratory system. Therefore, option (a) is correct.