Answer: b) Aunts and uncles
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Explanation:
The term "disjoint" is another way of saying "mutually exclusive". If two sets are disjoint, then they have nothing in common. Put another way, if two sets are disjoint, then it's not possible to be part of both sets at the same time.
In this case, it is not possible to be both an aunt and an uncle simultaneously for any one person. So this is why choice B is the answer.
