You are writing a class called MusicBank. You may assume an existing class Album that implements Comparable. The class MusicBank requires an instance variable index capable of referencing a collection that holds band names and their albums. Band names are to be held in alphabetic order, and albums are to be looked up by band name. Some band names will be associated with more than one album. Which two of the following declarations could be used for index, given the above description? Select one or more: HashMap index; TreeMap index; Map index; SortedMap index; HashMap index;