generics one more doubt-stack overflow exception, C#

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//Title of this code
//Rextester.Program.Main is the entry point for your code. Don't change it.
//Compiler version 4.0.30319.17929 for Microsoft (R) .NET Framework 4.5

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;

namespace Rextester
{
    
    
   
        
        public class GenBase<T,V>
        {
            
           public T tbase;
           public V vbase;
           GenBase<T,V> g=new GenBase<T,V>();//Error line
             public GenBase()
           {
             
           }
               
            
           public GenBase(T t,V v)
           {
               tbase=t;
               vbase=v;
           }
             public GenBase(V v,T t)
           {
               tbase=t;
               vbase=v;
           }
             public GenBase(T t)
           {
               tbase=t;
               
           }
             public GenBase(V v)
           {
               
               vbase=v;
           }
            
            public void BDisplay()
            {
                Console.WriteLine("Base_t: "+tbase);
                Console.WriteLine("Base_v: "+vbase);
                
            }
            
            
        }
        
        public class GenDerive<T,V>:GenBase<T,V> 
        {
             T tderiv;
             GenBase<T,V> g=new GenBase<T,V>();
            
            GenDerive<T,V> d=new GenDerive<T,V>();//Error line
            
             public GenDerive()
            {
             
            }
            
            public GenDerive(T t)
            {
                tderiv=t;  
                
            }
             public GenDerive(T t,V v):base(v)
           {
               tderiv=t;
               
           }
            public void DDisplay()
            {
                Console.WriteLine("Deriv_t: "+tderiv);
                Console.WriteLine("Base_v: "+vbase);
                
            }
            
        }
    public class Gen3<T,V>:GenDerive<T,V>
    {
        GenDerive<T,V> d=new GenDerive<T,V>();
        
         GenBase<T,V> bd=new  GenDerive<T,V>();
    }
     public class Program
    {
        public static void Main(string[] args)
        {
            GenBase<int,string> gb=new GenBase<int,string>(10,"Hello");
            GenBase<string,int> gb2=new GenBase<string,int>("Hello",10);
            GenDerive<string,int> gd=new GenDerive<string,int>("Hii",10);
            GenDerive<int,string> gd2=new GenDerive<int,string>(10,"Hii");
            gb.BDisplay();
            Console.WriteLine();
            gb2.BDisplay();
            Console.WriteLine();
            gd.DDisplay();
            Console.WriteLine();
            gd.BDisplay();
            Console.WriteLine();
            gd2.DDisplay();
            Console.WriteLine();
            gd2.BDisplay();
            
            
        }
    }
}

Show compiler warnings [ + ] Show input
Compilation time: 0.11 sec, absolute running time: 0.27 sec, cpu time: 0.06 sec, average memory usage: 24 Mb, average nr of threads: 6