reading question 8.1.1. let g be a group and let h be a subgroup of g. which of the following claims is true? select all that apply. (a) h is normal if and only if every left coset ah is equal to h. (b) h is normal if and only if if every left coset ah is equal to the corresponding right coset ha. 187 (c) h is normal if and only if it is abelian. (d) h is normal if and only if it has index 2. (e) h is normal if and only if it is closed under conjugation by elements of h. (f) h is normal if and only if it is closed under conjugation by elements of g.