Kennedy, Carter, and Jackson.
It is true that they had the different types of rule as the Italian city-states have always been very self-suficient in a way (mostly politically not so much economically). This lead to a system or method called autonamy where each city-state more or less had the right for self-government. This also depended on the area of life we're referring to.
Answer: B) So they can communicate their results without confusion
Explanation: There are other systems besides the metric system, though the metric is the most commonly used system. In the SI international system, all units are derived from each other, forming a unique international standard. That way, all scientists around the world, or at least most of them using the SI system, can communicate in a unique scientific "language" without confusion and misunderstanding.
OCEAN
Openess
Conscientiousness
Extraversion
Agreeableness
Neuroticism
