What will be the output of the following C# code snippet?

class UnsafeCode
{
    struct MyStruct
    {
        public int a;
        public int b;
        public int Sum() 
       { 
           return a * b; 
       }
   }
   unsafe static void Main()
   {
       MyStruct o = new MyStruct();
       MyStruct* p; 
       p = &o;
       p->a = 10; 
       p->b = 20; 
       Console.WriteLine("Value is " + p->Sum());
       Console.ReadLine();
   }

A. Compile time error

B. Run time error

C. 200

D. 30

Answer: Option C