Final answer:
The economic system of the new country aimed at optimizing economic efficiency, promoting egalitarianism, and preventing self-interest is indicative of a command economy.
Step-by-step explanation:
The new country's economy that is being considered for McDonald's expansion is focused on optimizing economic efficiency, promoting egalitarianism, and preventing self-interest. Based on these characteristics, the country's economic system is most aligned with a command economy. In a command economy, the government makes all the decisions regarding production and distribution of goods and services with the goal of achieving economic equality and efficiency, often at the expense of individual freedoms and the natural market dynamics present in a market economy. The scenario provided does not fit the description of a mixed economy, market economy, or socialistic economy, which tend to allow more room for individual self-interest and private enterprise. Therefore, the correct answer to the question is 'd. Command economy.'