Answer:
b.churches
Step-by-step explanation:
It was a great way to control the society and to enlarge their power, by supporting established churches rulers of different countries, in this time most rulers were monarch, that needed the support of the church to legitimate their power since they were rulers sent by God to rule over the kingdom, this is way the power of churches was helpful for the monarchies and this is why they decided to support them and gave them power.