Final answer:
The option that does not describe one of the four basic characteristics of a state is 'c. A state has a democratic system,' because having a democratic system is not a requirement for statehood.
Step-by-step explanation:
The question asks which option does not describe one of the four basic characteristics of a state. The four characteristics of a state are having a population, recognized boundaries, a government, and sovereignty. Thus, the incorrect option that does not describe a characteristic of a state is 'c. A state has a democratic system.'
It is important to note that while many states choose to have democratic systems, democracy is not a fundamental characteristic required for statehood. A government can take many forms, including democracy, monarchy, authoritarianism, etc. So, the essential characteristic of a state is that there is some form of government that has the authority to make and enforce laws, but the type of that government (democratic or otherwise) is not specified in the definition of a state.