Which of the following countries is considered to be a democracy

South Africa is a democratic country, it is also known as The Republic of South Africa. It has three-tier system of government composed of Judiciary, Legislative, and Executive authorities. 

The Executive authority is held by the President of South Africa, who serves as the head of state, head of government, and his cabinet. The Parliament of South Africa is held by the Legislative authority. They hold responsibility in electing the president to serve a fixed term. However, they differ in other democratic countries only in the way they handle their system of government in the national, provincial, and local governments. They assign a specific legislative and executive authority in their own spheres, unlike other countries where the President decides or the people decided who to specifically appoint in different regions through elections.

d is the logical answer but im not a 100% sure