A. The individual companies vary in size, from the corner grocery to the industrial giant.
B. Policies and management methods within firms range from formal well-planned organization and controls to slipshod day-to-day operations.
C. Various industries offer a wide array of products or services through millions of firms largely independent of each other.
D. Variation in the form of ownership contributes to diversity in capital investment, volume of business, and financial structure.
When $10^{100}$ is divided by 7, the remainder is ?