In Salesforce, a controller and extension for a custom object on a Visualforce page can be specified using the <apex:page> tag. The standardController attribute is used to associate the page with a standard or custom object, and the extensions attribute is used to specify an Apex class that extends the functionality of the standard or custom controller. The code snippet in option C, <apex:page standardController="Notice" extensions="myControllerExtension">, correctly demonstrates this by associating the Visualforce page with a custom object named "Notice" and specifying an extension named "myControllerExtension". References: You can find more information about controllers and extensions in the Visualforce Developer Guide and the [Apex Developer Guide] on Salesforce's official website.