Answer:
D. The civilization had a functioning government in place that decided the law of the land.
Step-by-step explanation:
The discovery of the official-looking seal and the clay tablet containing the laws which the civilization have to follow shows that they have a functioning government. This means that the society has a leader and they followed a set of rules.
It wasn't clearly stated in the statement whether the head was a king but it mentioned that the seal was much like what a king would use. So we cannot conclude that all civilizations were ruled by kings. This makes choice A incorrect.
Based on the information given, we're not sure whether it was the king who wrote the rules on the clay tablets. This makes choice B incorrect.
The statements above didn't show any evidence that the rulers were governors and not kings, so we cannot assume as well. This makes choice C incorrect.