The automation solution that would meet these requirements is Process Builder. Process Builder is a tool that can create and update records, send email alerts, submit records for approval, invoke flows, call Apex classes, and post to Chatter based on certain criteria and actions. The app builder can use Process Builder to create a process that starts when an opportunity is marked as closed won, creates a new opportunity record for the renewal with pre-populated fields, and sends an email alert to the contracts team. Option A is incorrect because an approval process is not suitable for this requirement, as approval processes are used to define the steps and criteria for approving records. Option B is incorrect because a validation rule is not suitable for this requirement, as validation rules are used to enforce data quality and prevent users from saving invalid records.
Option D is incorrect because a workflow rule is not suitable for this requirement, as workflow rules are considered legacy tools and have limitations compared to Process Builder.