If A is a proper subset of B, then A ∩ B =
Given, A is a proper subset of B
Let us consider two set as A is a proper subset of B
A = {9, 8, 7, 6, 5, 4} B = {1, 2, 3, 4, 5, 6, 7, 8, 9}
A ∩ B means we have write all the common elements of both the sets.
A ∩ B = {9, 8, 7, 6, 5, 4} ∩ {1, 2, 3, 4, 5, 6, 7, 8, 9}
= {4, 5, 6, 7, 8, 9}
The resultant set is same as A
Option A is the correct answer.