Which statement generates a list of Leads and Contacts that have a field with the phrase 'ACME'?

A developer has JavaScript code that needs to be called by controller functions in multiple Aura components by extending a new abstract component.
Which resource in the abstract Aura component bundle allows the developer to achieve this?

A developer Is asked to create a Visualforce page that lists the contacts owned by the current user. This component will be embedded In a Lightning page.
Without writing unnecessary code, which controller should be used for this purpose?

A lead object has a custom field Prior_Email__c. The following trigger is intended to copy the current Email into the Prior_Email__c field any time the Email field is changed:

Which type of exception will this trigger cause?

Which action can a developer perform in a before update trigger? (Choose 2)