4. The Roman Empire
( Muslim Empire is not a thing)
One of the biggest reasons was that there were some revolutions that happened around the lat 19th century. They were primarily sparked by lower class individuals who were looking for more money to support themselves/families.
Grain farming is done for economic activity and this makes it commercial. It is highly specialized and mechanised. The yield per acre is low so the farms are big. The yield is high per man so little manpower is needed for production. Grain farming is subject to market conditions like climate.
The subject of science is very broad. With that being said, I think there is no official regulatory board that decides the branches of science. Scientific developments are products of joined efforts of different scientists. These scientists could rebuke another's work provided there is evidence. As long as the theory is generally accepted by the scientists and no one rebukes it effectively, then it is a generally accepted fact and everyone adapts it.
Hence, the answer is B.
Because the earth is sphere
