Answer: The answer is (b) A is subset of B.
Step-by-step explanation: Two sets A and B are given as follows -
A = {1, 2, 3} and B = {3, 2, 1}.
The given options are
(i) 4 ∈ A. This is not correct, since 4 is a not in the set A.
(ii) A is a subset of B. This option is correct since every element of set A is in set B.
(iii) A is an infinite set. This is also not correct, since A has only 3 elements, so it is a finite set.
(iv) Since option (ii) is correct, so this option is incorrect.
Thus, the correct option is (ii) A is subset of B.
