Correct Answer: Farmers, Uncles, Males

Solution : Let's check each option –
First option: Brothers, Fathers, Uncles; some brothers can be fathers as well as uncles. It means all of them have a common area. Therefore, this is incorrect.
Second option: Farmers, Sisters, Brothers; some sisters and brothers can be farmers, but there is no relation between sisters and brothers. Therefore, this is incorrect.
Third option: Farmers, Uncles, Males; all uncles are males, so the circle of uncles lies completely inside the circle of males. Some males and uncles can be farmers so, the circle of the farmer has a common region between uncles and males.

Fourth option: Mothers, Females, Nephews; All mothers are females but the nephew is not related to the mother and females. Therefore, this is incorrect.

Hence, the third option is correct.