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

enum per
{
    married, 
    unmarried, 
    divorced, 
    spinster
}
per.married = 10; 
Console.WriteLine(per.unmarried);

enum color : byte
{
    red = 500,
    green = 1000,
    blue = 1500
}

String s1="Kicit";
Console.Write(s1.IndexOf('c') + " "); 
Console.Write(s1.Length);

String s1 = "ALL MEN ARE CREATED EQUAL";
String s2;
s2 = s1.Substring(12, 3); 
Console.WriteLine(s2);

1. Single f = 9.8f; 
   String s;
   s = (String) (f);

2. Single f = 9.8f; 
   String s;
   s = Convert.ToString(f);

3. Single f = 9.8f; 
   String s;
   s = f.ToString();

4. Single f = 9.8f; 
   String s;
   s = Clnt(f);

5. Single f = 9.8f; 
   String s;
   s = CString(f);

enum color
{
    red,
    green,
    blue 
}
color c; 
c = color.red; 
Console.WriteLine(c);

enum color
{
    red,
    green,
    blue 
}
color c = color.red;
Type t;
t = c.GetType();
string[ ]str;
str = Enum.GetNames(t);
Console.WriteLine(str[ 0 ]);

enum color: int
{ 
    red,
    green, 
    blue = 5, 
    cyan,
    magenta = 10, 
    yellow 
}
Console.Write( (int) color.green + ", " ); 
Console.Write( (int) color.yellow );

1. To use the keyword enum, we should either use [enum] or System.Enum.
2. enum is a keyword.
3. Enum is class declared in System.Type namespace.
4. Enum is a class declared in the current project's root namespace.
5. Enum is a class declared in System namespace.

enum color : int
{
    red = -3,
    green,
    blue 
}
Console.Write( (int) color.red + ", "); 
Console.Write( (int) color.green + ", "); 
Console.Write( (int) color.blue );