Which of the conversions are valid for the following C# code?

static void Main(string[] args)
{
    int a = 22;
    long b = 44;
    double c = 1.406;
    b = a;
    c = a;
    a = b;
    b = c;
}

A. int B. string C. double D. character

A. ; B. : C. . D. ,

A. num = int; B. var num; C. num int; D. int num;

A. Declares a constant B. Converts a variable to string C. Implicitly declares a variable D. Defines a method