B. ApexPages.CurrentPage().getParameters().put(‘input’, ‘TestValue’);

• This statement is useful for setting parameters on the current page, which simulates the passing of parameters from the initial URL to the controller. This is essential for testing how the controller handles input data that is passed via URL parameters.

D. String nextPage = controller.save().getUrl();

• This statement is useful for simulating the save action and capturing the resulting URL. This allows you to verify that the controller’s save method is functioning correctly and that it redirects to the expected page.

E. Test.setCurrentPage(pageRef);

• This statement sets the context to a specific Visualforce page reference. It’s essential for simulating different stages of the Visualforce Wizard and ensuring that the controller behaves correctly when different pages are loaded.