In fairness to the Java version, you should probably add all the additional stuff.

   using System.Linq;
   class Filter
   {
       static void Main()
       {
           var a = new []{1, 2, 3, 4}.Where(x=>x%2==0);
           System.Console.WriteLine(a);
       }
   }

It's unclear if printing is necessary or not, as the Java one does an explicit print, but the others don't.