Final answer:
The sole proprietor of the Milwaukee Machine Company cannot be determined without additional context. Sole proprietorship is a type of business where the owner and the business are legally the same, with the owner being fully responsible for the business.
Step-by-step explanation:
The question you've asked pertains to the owner of a business, specifically the Milwaukee Machine Company. Without further context, such as access to current business registration records or the context in the material you are studying, it's not possible to accurately determine who the sole proprietor is from the options provided. Sole proprietorship is a type of business entity that is owned and run by one individual and there is no legal distinction between the owner and the business. The sole proprietor takes all the decisions and bears the full responsibility for the business operations and debts.