A thermostat is a device used to adjust the temperature indoors. Which of the following explanations best interprets the author's intended meaning in the bolded words in following sentence?

"The Church was a thermostat that transformed the mores of society."

Society needs more churches in order to be truly transformed.
The church measured the morals of individuals within a society.
The church had power to influence what happened in society.
Society was a reflection of what was happening within churches.

In the excerpt "The Church was a thermostat that transformed the mores of society.", the author is comparing the function of a thermostat, that is to regulate and maintain the temperature of a place in some specific point, to the function of the church in relation to the mores, which means the function of the church as that of a thermostat is to regulate and maintain, in this case is not the temperature but the moral conventions and customs (mores). This implies, it was the church the one that decided whether moral or customs change and at what point they were modified, which means church had a power to determine what happened in society, especially in the way people behaved.