Mark is an excellent cook. He does not have any formal training but learned to cook by following the recipes of several famous chefs and his mom. Every weekend, he invites friends over for dinner so he can try new dishes and get honest feedback from his friends. Mark wants to start his own restaurant someday because he thinks he would be successful and become wealthy. Which of Adam Smith’s ideas made Mark think of starting a restaurant?

a) invisible hand
b) self-interest
c) competition
d) laissez-faire