using TestingProgram.Data;
using TestingProgramBusinessLogic;


Экземпляр класса
private TestManager test_managertest_manager = new TestManager(new Variants());

Подписка на события
test_manager.Messaging += test_manager_Messaging;

private void test_manager_Messaging(object sendler, TestingEventArgs e)
        {
            switch (e.TestStatus)
            {
                case TestStatus.EndOfTime:
                case TestStatus.EndOfTryCount:
                    {
                        ResetFormState();
                        MessageBox.Show(e.Message, "Ошибка!");
                        labelAttemptHint.Text = e.Message;
                        break;
                    }
                case TestStatus.WrongAnswer:
                    {
                        MessageBox.Show(e.Message, "Ошибка!");
                        labelAttemptHint.Text = e.Message;
                        break;
                    }
                case TestStatus.Complete:
                    {
                        ResetFormState();
                        MessageBox.Show(e.Message, "Поздравляем!");
                        labelAttemptHint.Text = e.Message;
                        break;
                    }

                default:
                    break;
            }
        }

Получение варианта
IVariant variantTemp = test_manager.StartTest(3, 45);
            if (variantTemp is Variant )
            {
                Variant variant = variantTemp as Variant;
                BuildTabelVariant(variant);
            }