Ques: Universal container (UC) has integration with its accounting system that creates ten thousand of orders inside salesforce in a nightly batch. UC wants to add automation that can attempt to match leads and contacts to these orders using email address field on the insert. UC is concerned about the performance of the automation with large data volume.

Which tool should UC use to automate this process?

Ans: Workflow rules
Process builder with an autolunached flow
Apex
Process Builder.
 

Please tell me correct answer.