In the early 19th century, the Russian government sent doctors to southern Russian villages to provide assistance during a cholera epidemic. The villagers noticed that wherever doctors appeared, people died. Therefore, many doctors were chased away from villages, and some were even killed. This reaction to the correlation between doctors and deaths is most likely a problem of .
a) omitted variables
b) reverse causality
c) government propaganda
d) medical incompetence

Option A

Explanation:

It is not that the doctors are not competent ,they were sent by the government, the government can't send incompetent doctors to solve an epidemic ,but it is going to be ommited variables by the doctors on the sickness, yes it takes time to figure out the root of sickness, looking at the period of early 19th century, medical method might not have reached a convincing level ,so there is possibility of omitted variables, maybe there were not able to have much time to figure out the sickness that might caused the death. So option A is the best possible answer.

every society, in order to meet the needs of it's people, has to answer three basic questions:

- what should we produce?

- how should we produce it?

- for whom should we produce it?

this questions must be answered in order to, option b, aid in production decisions.

every country can't produce everything, no matter how rich their land is. it may be a matter of technology, resources or geographical conditions. so, these three questions must be resolved in order to get the most of the production of each land.

hope this !

the atm that sounds like it should be the answer