A developer has a Visual force page that automatically assign ownership of an Account to a queue save. The page appears to correctly assign ownership, but an assertion validating the correct ownership fails.
What can cause this problem?

users complain that a page Is very slow to respond. Upon investigation, the query below Is found to perform slowly.
SELECT id, Name FROM Contact WHERE CustomField_c null;
Which two actions can a developer take to improve performance?
Choose 2 answers

What is the best way to display field-level error messages in Lightning?

A managed package uses a list of country ISO codes and country names as references data in many different places.. managed package Apex code.
What is the optimal way to store and retrieve the list?

A developer created three Rollup Summary fields: Total_timesheets_c, Total_Approved_timesheet_c and Total_project_Timesheet_c in the custom object, project _c Now, the developer is tasked with created a new field to show the ratio between and approved