Answer:
EventHandler
Step-by-step explanation:
In order to do this the programmer needs to use the EventHandler class. This class allows the computer to listen for certain user actions such as pressing a button. Using this on a button would then allow the programmer to specify what they want to happen when the user clicks the button or performs a certain action. For example, in this scenario, the programmer would program an EventHandler so that when the button is clicked it saves the input to a variable and changes the input field to the next option.