The ans is b.
Let's take an example,A={1,2,3,4,6}.
Relation(R) on A ={(a,b):a divides b} or b%a =0. Therefore R={(1,2),(2,4),(3,6)}.
A symmetric closure on R i.e R* should satisfy 3 conditions:-
- It should contain R
- It should be symmetric
- It should be minimal
Therefore R*={(1,2),(2,4),(3,6),(2,1),(4,2),(3,6)} which can be also written as R*={(x,y):either x divides y or y divides x}.
So,(B) is the right option to go for.