Which type of code represents the Model in the MVC architecture on the Force.com platform?

A developer needs to create a custom Visualforce button for the Opportunity object page layout that will cause a web service to be called and redirect the user to a new page when clicked. Which three attributes need to be defined in the <apex:page> tag of the Visualforce page to enable this functionality? Choose three answers.

An Apex method, getAccounts, that returns a List of Accounts given a searchTerm, is available for Lightning Web components to use.
What is the correct definition of a Lightning Web component property that uses the getAccounts method?

Which two ways can a developer instantiate a PageReference in Apex? Choose 2 answers

Opportunity opp=[select id ,stagename from opportunity limit 1] Given the code above, how can a developer get the label for the stagename field?