Final answer:
UCI leads the country in the number of students with 80,000 students.
Step-by-step explanation:
The answer to the question is 4. 80,000. UCI leads the country in the number of students with 80,000 students. According to the given information, the California Community Colleges system is the largest higher education system in the country, with 1.8 million students. However, the question specifically asks about UCI, not the entire system. Therefore, the answer is 80,000.