Which use case can only be performed by using asynchronous Apex?

A company accepts orders for customers in their enterprise resource planning (ERP) crder__c records with a lookup field to Account. The Account object has an External ID field, ERP_Customer_ID__c.
What should the integration use to create new Order__c records that will automatically be related to the correct Account?

A developer is creating a page in App Builder that will be used in the Salesforce mobile app.
Which two practices should the developer follow to ensure the page operates with optimal performance?
Choose 2 answers

As part of point-to-point integration, a developer must call an external web service which, due to high demand, takes a long time to provide a response. As part of the request, the developer must collect key inputs from the end user before making the callout.
Which two elements should the developer use to implement these business requirements?
Choose 2 answers

The Contact object in an org is configured with workflow rules that trigger field updates. The fields are not updating, even though the end user expects them to. The developer creates a debug log to troubleshoot the problem.
What should the developer specify in the debug log to see the values of the workflow rule conditions and debug the problem?