Do you think a free market or a command economy is more likely to encourage
productive and entrepreneurial behavior?
What does opportunity have to do with these
behaviors?

Free market is the best way to foster economic growth and entrepreneurial behavior. The free markets provide opportunity for smart but poor people to rise up and become rich. It also means the government does less things, which in the case of SpaceX, is great because Elon Musk has demonstrated that a private company is capable of beating the US Government in terms of space exploration.

The correct answer is: it shows that ancient humans hunted the now exinct creatures.