Answer:
A
Explanation:
A: This is the best choice. She will get a survey sample of many students from different grades and the sample will be random. This will give accurate and unbiased results.
B: This would only give results of students in a math class, so the results would be biased.
C: This would only be surveying seventh grade students, when there are also other grades in the middle school. This would not give accurate results.
D. The question states that Nicole is surveying opinions of students. Asking the teachers, especially only the teachers in one hallway, will definitely not help to find the opinions of students.
Therefore, the correct choice is A: Random students as they enter school