In the modern materialistic society, the only aim of people appears to be ...... money by fair means or foul.

In the modern materialistic society, the only aim of people appears to be acquire money by fair means or foul.
In this context, "acquire" means to obtain or gain possession of something, in this case, money. The sentence suggests that in a materialistic society, people prioritize obtaining money, whether through honest or dishonest methods. Therefore, "acquire" is the correct choice to complete the sentence, accurately conveying the pursuit of wealth as the primary goal in such a society.