Answer: Current owner ,customers and suppliers
Explanation:
Current owner is the person to whom the business property belongs presently.He will be knowing the complete information about the selling of retail business firm.
Customers and suppliers have the information in form of review of the business which might not have been told by business owner. They can determine the status, feedback and position of business .
According to the question, Tabitha should contact present owner of the business, customers and suppliers of the business for knowing about their opinions and reason for sale of successful establishment.