Let G be a finite group and H is a subgroup of G then Which of the following statements must be true?
1
If H is a normal subgroup of G, then every left coset of H in G is also a right coset.
2
If H is a proper nontrivial subgroup of G, then H cannot be a normal subgroup of G.
3
If H is a normal subgroup of G, then H must be a cyclic group.
4
If all the subgroup of the group is normal subgroup then group is abelian