What is the result of the debug statements in testMethod3 when you create test data using testSetup in below code?

A visualforce page uses the contact standard controller. How can a developer display the name from the parent account record on the page?

A developer writes a SOQL query to find child records for a specific parent. How many levels can be returned in a single query?

Universal Containers has implemented an order management application. Each Order can have one or more Order Line items. The Order Line object is related to the Order via a master-detail relationship. For each Order Line item, the total price is calculated by multiplying the Order Line item price with the quantity ordered.
What is the best practice to get the sum of all Order Line item totals on the Order record?

A developer needs to avoid potential system problems that can arise in a multi-tenant architecture. Which requirement helps prevent poorty written applications from being deployed to a production environment?