To automate the process of sending an approval request when an Account record changes from Prospect to New Customer, the best approach would be to use Salesforce Flow to update the Account field value and then trigger an Approval Process to notify the VP of Sales. This approach allows for a more flexible and powerful automation compared to using Apex Triggers or Process Builder alone. Salesforce Flow can detect record changes and perform complex logic, including updating records and initiating approval processes. The Approval Process can then be configured to send an approval request to the VP of Sales. This solution aligns with Salesforce's best practices for leveraging declarative automation tools before resorting to code.Reference: Salesforce Help Documentation on Flow and Approval Processes.