UPSC NDA Math Model Paper 10

Taking any arbitrary example
Let A = {1, 3}, B = {3} and C = {1, 2, 3, 4, 5, 6}
Now, A ∪ B = {1, 3}
Case 1: If x = 3 , then x ∈ A, and A ∉ B, but x ∈ B (option 1 false)
Case 2: If x = 3 , then x ∉ A, and B ⊂ A, then x ∉ B (option 2 true)
Case 3: A ⊂ C and B ⊂ C, but A ≠ B (option 3 false)
Case 4: A ⊂ C and B ⊂ C, but (A ∪ B) ≠ C (option 4 false)