The correct answer is - a collection of small kingdoms and city-states.
Italy, in the 15th century, was not a unified country, but instead, there were numerous small kingdoms and city states on its territory. These small kingdoms and city-states were varying in military and economic power, but in general, for small territories, they were respectably powerful.
All of these small kingdoms and city-states were ruled by local powerful families, whose main occupation was usually trade, apart from the Papal state, where the leader was the Pope of the Catholic church.