To initiate sends when contacts for select accounts are created, Northern Trail Outfitters should use a Salesforce Data Entry Source on the Contact Object. A Salesforce Data Entry Source is a feature that allows marketers to inject contacts into a journey based on changes or events in Sales Cloud objects, such as contacts or accounts. Using a Salesforce Data Entry Source on the Contact Object will allow Northern Trail Outfitters to trigger sends when a contact record is created for a specific account. Reference: https://help.salesforce.com/s/articleView?id=sf.mc_jb_salesforce_data_event.htm&type=5