What impact did Mongol leaders Genghis Khan and Kublai Khan have on Europe? A.
They introduced Eastern culture and literature to Europeans.
B.
Their armies raided and destroyed European cities.
C.
The Mongol leaders brought and spread Christianity in Europe.
D.
The khans and their armies taught Europeans modern warfare.

i might be wrong but i'm 97% sure it's B.

Explanation:

It's definitely not C because they didn't believe in christianity.

a punishment or the threat of punishment used to enforce conformity. enforcement of norms or shared rules of conduct that tell people how to act in specific situations. social control. not everyone internalizes all of society's norms, and some people must be motivated by self-fulfillment.

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.