如何在实体框架4中的poco中定义集合?

假设我有一个 团队 包含 0以上 球员 .

这个 运动员 上课很容易:

public class Player
{
    public long Id { get; set; }
    public string Name { get; set; }
    public Team Team { get; set; }
}

但是什么是最好的定义 团队 班级?

选项1

public class Team
{
    public long Id { get; set; }
    public string Name { get; set; }
    public ICollection<Player> Players { get; set; }
}

选项2:

public class Team
{
    public Team()
    {
        Players = new Collection<Player>();
    }

    public long Id { get; set; }
    public string Name { get; set; }
    public ICollection<Player> Players { get; set; }
}

选项3:

public class Team
{
    public long Id { get; set; }
    public string Name { get; set; }
    public IQueryable<Player> Players { get; set; }
}

选项4:

public class Team
{
    public long Id { get; set; }
    public string Name { get; set; }
    public ObjectSet<Player> Players { get; set; }
}