problem c#

using System; using System.Collections.Generic; using System.Text; namespace ConsoloAPP2._199 { class Product { public int ProductId { get; set; } public string ProductName { get; set; } public int AvailableQuantity { get; set; } public decimal...

hello i have a problem with the task. Here is the content of the task: The account creation process is as follows: 1. validating email address 2.checking if the email is free (email is a unique user identifier) 3.Adding a user to the database (a list for the purpose of the task) 4.sending an...