Let's look over the meaning of each option:
Theocracy: Theo- means that it is relating to religion. For example, Theology is the study of religion. This is a system where religious leaders control the country, but it is NOT an economic system.
Monarchy: Monarchy is when there is a king, queen, emperor, etc. It is not an economic system either.
Fundamentalism: A political system that strictly abides by a set of fundamentals. Someone who wants a constitution to be the highest form of law is a fundamentalist. However, this is also not an economic system.
Socialism: WINNER WINNER CHICKEN DINNER! Socialism is a system similar to communism where the government controls the economy and there is communal ownership. This is also the only option which is both a political and economic system.
TL;DR: The answer is Socialism.
