Which three web technologies can be integrated into a Visualforce page? Choose 3 answares

What is a benefit of the lightning component framework?

For which three items can a trace flag be configured? (Choose three.)

Which Apex collection is used to ensure that all values are unique?

A developer is tasked with performing a complex validation using Apex as part of advanced business logic. certain criteria are met for a PurchaseOrder, the developer must throw a custom exception.
What is the correct way for the developer to declare a class that can be used as an exception?