70-518 Question #19: Real Exam Question with Answer & Explanation

You are developing a Windows application by using Microsoft .NET Framework 4. You plan to design a diagnostic logging strategy that will be used in a production environment. You need to ensure that the strategy meets the following requirements: - Enables or disables diagnostic messages by using an application configuration option. - Changes the level of detail in the diagnostic messages without recompiling the application. Which class should you use?