The correct answer is C. acquire.
To acquire something means to get it as your own. In the context of the question, people in the modern materialistic society are only interested in getting money, regardless of how they get it. This can be done through fair means, such as working hard and earning money through honest means. However, it can also be done through foul means, such as stealing, cheating, or even resorting to violence.
The other options are incorrect because they do not accurately reflect the meaning of the question. Option A, print, is incorrect because it does not make sense to say that people are only interested in printing money. Option B, produce, is incorrect because it does not make sense to say that people are only interested in producing money. Option D, extort, is incorrect because it does not make sense to say that people are only interested in extorting money.
In conclusion, the correct answer to the question is C. acquire.