In 1954, an American called Ray Kroc was selling milk machines. Most restaurants bought one or two of these machines, but one restaurant ordered eight of them. Kroc was surprised at this big order. He decided to visit the restaurant.
It was a small hamburger stand (汉堡包销售点). A group of young people in clean, white unisons(制服) were at work. They were happy, fast and polite. People kept coming to buy food. Kroc thought this was a very successful business. He looked up at the name over the door. It read, "McDonald’s Hamburgers".
Kroc found out that two brothers owned the business. They were called Mac and Dick McDonald. He suggested that they should set up more restaurants, but the brothers were happy with their life, and they themselves did not want to. However, they let Kroc set up other restaurants for them. That was the start of the biggest fast food company. In 1955, Kroc opened his first McDonald’s near Chicago. Four years later,the 100th McDonald’s was opened. In 1961 Kroc bought all rights(权利) to McDonald’s from Mac and Dick.By 1972, a new McDonald’s was opened every day. By 1974, there were over 3000 McDonald’s around the world.

Kroc decided to visit "McDonald’s Hamburgers" because ()

A. it was a clean restaurant and sold good food
B. the workers in the restaurant were fast and polite
C.it bought more milk machines from him than other restaurants