To referencethe string type in programs, we can have several choices: 1. including a “using System” /**//* String */Using System;public class stringExample1...{ static void Main() ...{ String vv = "I’m a string!"; }} 2. No “using ” directive included /**//* System.String */// No "using" directive needed!public class stringExample2...{ static void Main() ...{ System.String vv = "I’m a string too!"; }} 3. No “using ” directive included /**//* string */// No "using" directive needed!public class stringExample3...{ static void Main() ...{ string vv = "I’m the simplest string!"; }}