Which code segment should you insert at line 02?

Verified the answer using Visual Studio. C is the only one that compiles and doesn’t throw an exception during runtime:

public class League
{
public string LeagueName { get; set; }
public List Teams = new List();
}

public class Team
{
public string TeamName { get; set; }
public List Players = new List();
}

public class Player
{
public string FullName { get; set; }
}

void main()
{
Player player1 = new Player() { FullName = “Player1” };
Player player2 = new Player() { FullName = “Player2” };
Player player3 = new Player() { FullName = “Player3” };
Player player4 = new Player() { FullName = “Player4” };
Player player5 = new Player() { FullName = “Player5” };
Player player6 = new Player() { FullName = “Player6” };
Player player7 = new Player() { FullName = “Player7” };
Player player8 = new Player() { FullName = “Player8” };

Team team1 = new Team() { TeamName = “Team1” };
team1.Players.Add(player1);
team1.Players.Add(player2);
Team team2 = new Team() { TeamName = “Team2” };
team2.Players.Add(player3);
team2.Players.Add(player4);
Team team3 = new Team() { TeamName = “Team3” };
team3.Players.Add(player5);
team3.Players.Add(player6);
Team team4 = new Team() { TeamName = “Team4” };
team3.Players.Add(player7);
team3.Players.Add(player8);

League league1 = new League() { LeagueName = “League1” };
league1.Teams.Add(team1);
league1.Teams.Add(team2);

League league2 = new League() { LeagueName = “League2” };
league2.Teams.Add(team3);
league2.Teams.Add(team4);

List leagues = new List();
leagues.Add(league1);
leagues.Add(league2);

var query = leagues.SelectMany(l => l.Teams.SelectMany(t => t.Players));

foreach (Player player in query)
Debug.WriteLine(player.FullName);
}

OUTPUT:
Player1
Player2
Player3
Player4
Player5
Player6
Player7
Player8