The correct answer to this question is A, Monarchy. This single person also performs ceremony duties and is a symbol of the country that they are in control of. When the person in charge passes away, someone else in the family will take charge and become the ruler.
Like all governments, there are both pros and cons. One pro is that decisions are made quickly because just one person is making the decision. When a decision is made, the person in charge generally has everyone's interests in mind, which means the majority of the people are happy. However, the downside is that you can have a ruler who takes the abuse of the power that they have.