Let G be a group, |G| = n in N, and H is a subset of G. Then all that is necessary to show that H<=G is that: a. H is closed b. H is closed and has the inverse property c. H is closed, has the inverse and identity properties, d. H is closed, has the inverse, identity, and associativity properties Solution d. H is closed, has the inverse, identity, and associativity properties.