Let n=4 ,so indexes from 1 to 4.
Ex 1 - A[3,2,1,4] then B is B[3,2,1,4]
Ex 2 - A[4,2,1,3] then B is B[3,2,4,1]
From the examples above
Option C - Doing the same transformation twice will not give the same array. is proven false by Ex 1. As A=B.
Option A - B will be a sorted array. is proven false by Ex 2.
Option B - B is a permutation of array A.
From google - meaning of permutation - "each of several possible ways in which a set or number of things can be ordered or arranged.". As we see both Ex 1 and Ex 2 B's are permutations of their A's.
Option D - is false if option B is True.
So Answer is option B.