Which of the following statements are correct about data types?

1. Each value type has an implicit default constructor that initializes the default value of that type.
2. It is possible for a value type to contain the null value.
3. All value types are derived implicitly from System.ValueType class.
4. It is not essential that local variables in C# must be initialized before being used.
5. Variables of reference types referred to as objects and store references to the actual data.

class Sample
{
    int i;
    Single j;
    double k;
    public Sample (int ii, Single jj, double kk)
    {
        i = ii;
        j = jj;
        k = kk;
    } 
}

namespace CuriousTabConsoleApplication
{ 
    class SampleProgram
    {
        static void Main(string[] args)
        { 
            int num = 1;
            funcv(num); 
            Console.Write(num + ", "); 
            funcr(ref num); 
            Console.Write(num + ", ");
        }
        static void funcv(int num)
        { 
            num = num + 10; Console.Write(num + ", ");
        }
        static void funcr (ref int num)
        { 
            num = num + 10; Console.Write(num + ", ");
        } 
    } 
}

1. true
2. false
3. new
4. ~
5. sizeof

int i = 20 ;
for( ; ; )
{
    Console.Write(i + " "); 
    if (i >= -10)
        i -= 4; 
    else 
        break;
}

1. static
2. protected
3. private
4. shared
5. public

1. Integer
2. Array
3. Single
4. String
5. Long

byte a = 11, b = 22, c;