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Answer:</h2>
Option: B is the correct answer.
B. Every member of the boys’ basketball team
<h2>
Step-by-step explanation:</h2>
We know that a biased sample is one in which the sample is not random.
There is some partiality or some preference of choosing a member of a sample.
A.) Every tenth boy on the school’s phone list.
As the choosing of the members of a sample is random i.e. each student has an equal probability of getting chosen.
Hence, the sample is not biased.
C.) Every boy in a randomly selected ninth-, tenth-, eleventh-, and twelfth-grade gym class.
Again this sample is random.
Hence, the option is incorrect.
D.) Every fifth boy who walks through the front doors of the school in the morning.
In this sample every person has an equal probability.
Hence, the sample is not biased.
B.) Every member of the boys’ basketball team.
This is a biased sample since the members in the basketball team have a big height and hence their foot size is also big. So, we can't obtain a good result for determining the average shoe size of all the male students in the school.
Hence, the sample is biased.