Final answer:
Corporations have the greatest volume of sales in the United States, outweighing other forms of business organizations like sole proprietorships and partnerships, and include major entities like Walmart and Microsoft.
Step-by-step explanation:
The type of business organization with the greatest volume of sales in the United States is corporations. While many might initially think of sole proprietorships or partnerships when it comes to business organizations, it is the corporate giants like Wal-Mart, Microsoft, and General Motors that dominate in terms of sales volume. Corporations, which can be either public or private entities, have the capacity to grow much larger than the other types of businesses, influencing not only the economy but also cultural attitudes and fashions internationally. Despite the vast majority of businesses in the U.S. being smaller firms with fewer than 20 employees, these large corporations account for a significant portion of the total sales.