Independent workers; tax preparer working his own business and freelance writers.
Explanation:
A sole proprietorship is also known as individual entrepreneurship and it´s a type of enterprise run by one person only, there is no legal distinction between the business and the person in charge. The proprietor is the receiver of all the profits but also responsible for all the losses and debts. It´s not necessary for the person in charge to work alone, it is possible to employ other people. The other examples given are examples of partnerships in which there are at least two owners. In that case, the responsibility is divided.