Answer:
Their main purpose has been to A. commemorate rulers and other important individuals.
Explanation:
Statues are usually put up to honor individuals of a high status. For example, in Greece, they were put up to honor gods and goddesses.
As we can see, a statue is usually a very flattering sculpture, showing the individual in his/her best and almost god-like self. This is why historically they have fulfilled the purpose of commemorating important individuals.