A customer has a single Visualforce page that allows each user to input up to 1500 sales forecasts and instantly view pivoted forecast calculations. Users are complaining that the page is loading slowly, and they are seeing error messages regarding heap and view state limits.
What are three recommendations to optimize page performance? (Choose three.)
A developer wrote an Apex class to make several callouts to an external system.
If the URLs used in these callouts will change often, which feature should the developer use to minimize changes needed to the Apex class?
