Did any one person or class hold the most power during the middle ages, or did it shift back and forth?

During the middle ages, the nobles or royalty held most of the power while also sharing a good part of it with the church. The church was followed by everyone while the royalty had limited control over the church. In a way it shifted back and forth but it was mainly in the hands of one ruler.

the effect of the ming leaders banning ships with more than two masts was that there was no further construction of ships masts, because there was a surplus. ming emperors disallowed foreign exploration

answer is a. counterclaims