using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

​

        List<Product> products = new List<Product>

        {

            new Product { ID = 1, Name = "Apple", Category = "Fruits" },

            new Product { ID = 2, Name = "Carrot", Category = "Vegetables" },

            new Product { ID = 3, Name = "Banana", Category = "Fruits" },

            new Product { ID = 4, Name = "Lettuce", Category = "Vegetables" },

            new Product { ID = 5, Name = "Orange", Category = "Fruits" }

        };

        var groupedAndOrderedProducts = products

            .GroupBy(p => p.Category)

            .OrderBy(g => g.Key)

            .Select(g => new

            {

                Category = g.Key,

                Products = g.OrderBy(p => p.Name)

            });

​

        foreach (var group in groupedAndOrderedProducts)

        {

            Console.WriteLine($"Category: {group.Category}");

            foreach (var product in group.Products)

            {

                Console.WriteLine($" - {product.Name}");

            }

        }

​

​

​

    }

}

public class Product

{

    public int ID { get; set; }

    public string Name { get; set; }

    public string Category { get; set; }

}

​

​