The correct answer is - D. oligarchy.
When a small group has a firm control over a country, than we are talking about an oligarchical government. In the oligarchical government type, there's a small number of people that control pretty much everything in the country. The industry, agriculture, natural resources, mediums, every import sector of is control by only few individuals that are very powerful, and dictate everything in the country, often through a mutual agreement.
