using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    public class Product

    {

        public List<Option> Options { get; set; }

        public List<List<string>> GetAllCombinations()

        {

            if (Options == null || !Options.Any())

            {

                return new();

            }

            var combinations = new List<List<string>> { new() };

            foreach (var option in Options)

            {

                combinations = combinations

                    .SelectMany(combination => option.Values

                        .Select(optionValue => new List<string>(combination) { optionValue }))

                    .ToList();

            }

            return combinations;

        }

    }

    public class Option

    {

        public string Name { get; set; }

        public List<string> Values { get; set; }

    }

    public static void Main()

    {

        Product product = new()

        {

            Options = new()

            {

                new() { Name = "Color", Values = new() { "Blue", "Yellow", "Green" } },

                new() { Name = "Memory", Values = new() { " 32 GB", " 64 GB", "128 GB" } },

                new() { Name = "Display", Values = new() { " HD", "FHD", "UHD" } },

            }

        };

        var combinations = product.GetAllCombinations();

        foreach (var combination in combinations)

        {

            Console.WriteLine(string.Join("", combination.Select(comb => comb.PadRight(10))));

        }

    }

}