You work as an Enterprise Application Developer for ABC Inc. The company uses Visual Studio 2008 as its application development platform. You create a web application using .NET Framework 3.5. You…

You work as an Enterprise Application Developer for ABC Inc. The company uses Visual Studio 2008 as its application development platform. You create a web application using .NET Framework 3.5. You have created a form named Form1. You have added Textbox controls for taking Name, Address, and Phone Number of user as input in Form1. You want to ensure that a user enters a value in the Name field. Which of the following validation server controls will you use to accomplish the task?