Create Nested query on object list in CSharp

using System;//w ww. j  av  a2  s  .c  o m
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.Linq;
using System.Reflection;

class Person
{
    int _id;
    int _idRole;
    string _lastName;
    string _firstName;

    public int ID
    {
        get { return _id; }
        set { _id = value; }
    }

    public int IDRole
    {
        get { return _idRole; }
        set { _idRole = value; }
    }

    public string LastName
    {
        get { return _lastName; }
        set { _lastName = value; }
    }

    public string FirstName
    {
        get { return _firstName; }
        set { _firstName = value; }
    }
}
class MyRole
{
    int _id;
    string role;

    public int ID
    {
        get { return _id; }
        set { _id = value; }
    }

    public string Role
    {
        get { return role; }
        set { role = value; }
    }
}
class Program
{
    static void Main(string[] args)
    {
        List<Person> people = new List<Person> {
               new Person { ID = 1, IDRole = 1, LastName = "A", FirstName = "B"},
               new Person { ID = 2, IDRole = 2, LastName = "G", FirstName = "T"},
               new Person { ID = 3, IDRole = 2, LastName = "G", FirstName = "M"},
               new Person { ID = 4, IDRole = 3, LastName = "C", FirstName = "G"}
            };
        List<MyRole> roles = new List<MyRole> {
               new MyRole { ID = 1, Role = "Manager" },
               new MyRole { ID = 2, Role = "Developer" }
            };
        var query = people
                    .Where(p => p.ID == 1)
                    .SelectMany(p => roles
                                    .Where(r => r.ID == p.ID)
                                    .Select(r => new { p.FirstName, p.LastName, r.Role }));
    }
}