20. (15 points) Circle VALID (i.e., no error) or INVALID (1.e., error). Please answer the questions based upon the UMLs as well as the contents/codes we have discussed in class up to now. VALID / INVALID VALID / INVALID ListArrayBased lab = new ListArrayBased; ListReference Based Irb = new ListReferenceBased(); ListArrayBased lab = new ListReferenceBased(); ListReferenceBased lab = new ListArrayBasedo; Object obj = new ListArrayBased(); Object obj = new List ReferenceBasedo: VALID / INVALID VALID / INVALID VALID / INVALID VALID / INVALID Object obj = new Integer(); VALID / INVALID VALID / INVALID Object obj - new Queue ArrayBased; ListArrayBased lab = new Object(); List ReferenceBased Irb = new ObjectO; VALID / INVALID VALID / INVALID VALID / INVALID QueueArrayBased qrb = new Queue ArrayBased(); QueueReferenceBased qlb = new Queue Reference Based(); VALID INVALID ListInterface li = new ListInterface(); VALID / INVALID ListInterface li = new ListArrayBased; VALID / INVALID ListInterface li = new List ReferenceBased); VALID / INVALID Y The refer to the following UML diagrams More Array index starts from 0, not from 1 in ListArrayBased. 2) Notice that a new method, getHead), is defined in List Reference Based and you are asked to use it for some questions shift