Final answer:
The third largest category of exceptional students could refer to those with unique educational needs or abilities, often involving gifted or high-IQ students. The information does not directly answer the question, but based on provided context, this inference is made. Nations that excel in science and math commonly recruit top teachers to enhance student achievement.
Step-by-step explanation:
The third largest category of exceptional students is not explicitly stated in the information provided. However, based on the context which discusses resilient students, educational achievement, and intelligence quotients (IQs), it can be inferred that the term might refer to students with unique educational needs or abilities, such as those who are gifted or have learning disabilities. In the context of the U.S. educational system, it is often noticed that resources are inequitably distributed, which affects student performance. Therefore, the third largest category could be related to students who, despite the odds, manage to perform well academically—perhaps encompassing those with high IQs or are part of programs for gifted and talented individuals.
Regarding the nations that are top-ranked in science and math, the correct answer to the question about what these top-ranked nations have in common is: They recruit top teachers (Option b). This is a key factor contributing to high student achievement in these nations, as highly skilled educators are crucial in fostering student learning and critical thinking skills.