Select the set of classes of relationship among which is best illustrated by the following V enn diagram.

The correct option is Grandfathers, Fathers, Males.

Step-by-step Explanation:

1. Analyze the Venn diagram:
The given image shows three concentric circles, where the smallest circle is completely enclosed by the middle circle, and the middle circle is completely enclosed by the largest circle. This representation signifies a relationship where class C is a subset of class B, and class B is a subset of class A (i.e., C ⊂ B ⊂ A).

2. Evaluate the given options:
- Grandfathers, Fathers, Males: All grandfathers are fathers, and all fathers are males. Therefore, the set of 'Grandfathers' is entirely contained within the set of 'Fathers', which is entirely contained within the set of 'Males'. This perfectly matches the concentric circles structure.
- Fathers, Brothers, Males: Although both fathers and brothers are males, not all fathers are brothers, and not all brothers are fathers. Their circles would intersect within the larger 'Males' circle, but would not be concentric.
- Literates, Engineers, Farmers: All engineers are literates, but not all literates are engineers, and farmers only partially overlap with literates.
- Mothers, Aunt, Doctors: Not all mothers are aunts, and doctors only partially overlap with both mothers and aunts.

Thus, the relationship among Grandfathers, Fathers, and Males is best illustrated by the three concentric circles in the Venn diagram.