Final answer:
The correct comparative structure in the paragraph is a subject-by-subject structure where one subject is discussed fully before moving on to the next.
Step-by-step explanation:
The statement that most accurately describes the type of comparative structure used in the paragraph is option (d) It is a subject-by-subject structure because one career is fully discussed before moving on to the next. This is evident in the provided description that outlines discussing all points related to one subject before transitioning to the next. This organizational structure is typically used when each subject is complex or when the writer wants to discuss each subject in depth without going back and forth between them.