Read the excerpt from President Ronald Reagan’s Address at Moscow State University.

The explorers of the modern era are the entrepreneurs, men with vision, with the courage to take risks and faith enough to brave the unknown. These entrepreneurs and their small enterprises are responsible for almost all the economic growth in the United States. They are the prime movers of the technological revolution. In fact, one of the largest personal computer firms in the United States was started by two college students, no older than you, in the garage behind their home. Some people, even in my own country, look at the riot of experiment that is the free market and see only waste. What of all the entrepreneurs that fail? Well, many do, particularly the successful ones; often several times. And if you ask them the secret of their success, they'll tell you it's all that they learned in their struggles along the way; yes, it's what they learned from failing. Like an athlete in competition or a scholar in pursuit of the truth, experience is the greatest teacher.

Which is a substantiated opinion?
a. One of the largest computer companies began in a garage.
b. Small businesses are the reason America has a strong economy.
c. Experience is the best way for entrepreneurs to learn.
d. People are often wasteful in free market societies.