Consider the following code snippet for a Visualforce page that is launched using a Custom Button on the Account detail page layout. When the Save button is pressed the developer must perform a…

Consider the following code snippet for a Visualforce page that is launched using a Custom Button on the Account detail page layout. When the Save button is pressed the developer must perform a complex validation that involves multiple objects and, upon success, redirect the user to another Visualforce page. What can the developer use to meet this business requirement?