The above XML document is not well-formed.The document suffers from two errors which are as follows:1. Improper nestingThe MiddleName element is opened inside the FirstName element, yet MiddleName is not closed before the FirstName element is closed.2. Mismatched cases of start and end tagThe tag <lastname> is closed with </LastName>, which is incorrect. XML is case sensitive, thus the end tag of <lastname> should be </lastname>.