如何使用Linq删除List<>中的嵌套(子)项？

using System;
using System.Collections.Generic;
using System.Linq;

public class Item
{
    public int Id { get; set; }
    public string Name { get; set; }
    public List<SubItem> SubItems { get; set; }
}

public class SubItem
{
    public int Id { get; set; }
    public string Name { get; set; }
}

public class Program
{
    public static void Main()
    {
        List<Item> items = new List<Item>
        {
            new Item
            {
                Id = 1,
                Name = "Item 1",
                SubItems = new List<SubItem>
                {
                    new SubItem { Id = 1, Name = "SubItem 1" },
                    new SubItem { Id = 2, Name = "SubItem 2" }
                }
            },
            new Item
            {
                Id = 2,
                Name = "Item 2",
                SubItems = new List<SubItem>
                {
                    new SubItem { Id = 3, Name = "SubItem 3" },
                    new SubItem { Id = 4, Name = "SubItem 4" }
                }
            }
        };

        int subItemIdToRemove = 2;

        // 使用Linq删除List<>中的嵌套(子)项
        items.ForEach(item => item.SubItems.RemoveAll(subItem => subItem.Id == subItemIdToRemove));

        // 输出删除后的结果
        foreach (var item in items)
        {
            Console.WriteLine($"Item: {item.Name}");
            Console.WriteLine("SubItems:");
            foreach (var subItem in item.SubItems)
            {
                Console.WriteLine($"- {subItem.Name}");
            }
            Console.WriteLine();
        }
    }
}