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

namespace CuriousTabConsoleApplication
{ 
    class Sample
    { 
        public int index; 
        public int[] arr = new int[10]; 
        
        public void fun(int i, int val)
        { 
            arr[i] = val;
        }
    }
     
    class MyProgram
    { 
        static void Main(string[] args)
        {
            Sample s = new Sample(); 
            s.index = 20; 
            Sample.fun(1, 5); 
            s.fun(1, 5); 
        } 
    } 
}