Which of the following statements is correct about the C#.NET code snippet given below?

switch (id)
{
case 6:
grp = "Grp B";
break;
case 13:
grp = "Grp D";
break;
case 1:
grp = "Grp A";
break;
case ls > 20:
grp = "Grp E";
break ;
case Else:
grp = "Grp F";
break;
}