A conservative pair of sunglasses is permitted when authorized by whom?

The correct answer is that a conservative pair of sunglasses is permitted when authorized by the Naval Science Instructor (NSI). The NSI plays a pivotal role in establishing and enforcing the dress and appearance standards within the NJROTC program, ensuring that all uniforms and accessories maintain a level of professionalism and military decorum.

Authorization from the NSI signifies that the sunglasses fit within the guidelines set forth by the program for both functionality and aesthetic standards. This helps to promote uniformity among cadets while also allowing for individual expressions of style within a controlled framework. Other figures such as the Navy command, area manager, or school principal have separate responsibilities and authorities that do not specifically pertain to the direct management or oversight of uniform standards in the NJROTC program. Hence, it is the NSI that holds the appropriate authority in this context.