What are the security differences between ChatGPT Enterprise, Teams, and personal/free plans for handling client PII?

A participant reported that their firm recently invested in ChatGPT Enterprise and partnered with a security consultant, and found there are vastly different security profiles between Enterprise, Teams, and personal plans. They also paid for data residency to keep data stored in the United States rather than offshore. The segment cuts off before the consultant's full opinion on whether PII was acceptable under Enterprise is explained, so the conclusion is not captured here.