How to Apply LINQ Distinct on a particular property in C#?

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace AbundantcodeConsole
{

    class Program
    {
        static void Main(string[] args)
        {
            //How to App LINQ Distinct on a particular property in C# ? 
            List emps = new List();
            emps.Add(new Employee { Name = "Martin", Designation = "ACEngineer" });
            emps.Add(new Employee { Name = "Mike", Designation = "ACSeniorEngineer" });
            emps.Add(new Employee { Name = "Peter", Designation = "ACEngineer" });
            emps.Add(new Employee { Name = "Mark", Designation = "ACEngineer" });
            var employeeData = (from p in emps
                                group p by new { p.Designation }
                                    into distinctDesignationGroup
                                    select distinctDesignationGroup.First());

            foreach (var data in employeeData)
                Console.WriteLine(data.Name + " , " + data.Designation);
            Console.ReadLine();
        }
    }

    public class Employee
    {
        public string Name { get; set; }
        public string Designation { get; set; }
    }
}