Answer:
Option B - 90 students at random during lunch
Step-by-step
An unbiased sample is defined as:
A sample is an unbiased sample if every individual or the element in the population has an equal chance of being selected.
Based on this, we can eliminate:
Option A) - It prevents non-eighth-graders of the school from being represented.
Option C) - Students in a hallway might take a particular class together/may be of the same grade. This gives them an unfair advantage.
Option D) - All students who are not in chorus are not represented in this set.
