Uppercase only

Write a query that returns only uppercase words from string.
Expected input and output
"DDD example CQRS Event Sourcing" → DDD, CQRS
using System;
using System.Linq;

namespace CSharpExercises.Exercises.LINQ
{
    class UppercaseOnlyTask
    {
        public static void Main()
        {
            string word = "THIS is UPPERCASE string LOL";

            var uppercaseOnly = word.Split(' ').Where(x => string.Equals(x, x.ToUpper()));

            foreach (var u in uppercaseOnly)
            {
                Console.Write($"{u}, "); // THIS, UPPERCASE, LOL,
            }
        }
    }
}