Final answer:
A∩B represents students with a 4.0 GPA in both semesters, A is not necessarily a subset of B, and A∪B includes 4.0 GPA students from either semester. The correct answer is option A.
Step-by-step explanation:
The student's question touches on the concepts of set theory, specifically intersections, unions, and subsets. For part (a), A∩B (the intersection of sets A and B) is the set containing all students at Winfield College who had a 4.0 GPA in both the fall 2012 semester and the spring 2013 semester. For part (b), A is not necessarily a subset of B, as we don't have enough information to conclude that every student with a 4.0 GPA in the fall also had a 4.0 GPA in the spring. Lastly, for part (c), A∪B (the union of sets A and B) represents all students who had a 4.0 GPA in either semester, which includes students who had a 4.0 in just one semester as well as those who had a 4.0 in both semesters. Based on these explanations, the correct answer is option A: (a) 4.0 GPA students in both semesters, (b) Yes, (c) 4.0 GPA students in either semester.