A developer wants to call an Apex Server-side Controller from a Lightning Aura Component. What are two limitations to the data being returned by the Controller? Choose 2 answers

A Visualforce page needs to make a callout to get biding information and tax information from two different REST endpoints. The information needs to be Displayed to the user at the same time and the return value of the billing information contains the input for the tax information callout. Each endpoint might take up to two minutes to process.
How should a developer implement the callouts?

Which of these are valid REST annotations?

A company wants to create a dynamic survey that navigates users through a different series of questions based on their previous responses. What is the recommended solution to meet this requirement?

A developer created and tested a Visualforce page in their developer sandbox, but now receives reports that users are encountering ViewState errors when using it in Production. What should the developer ensure to correct these errors?