B, because there is quotations and you have to start a new line when someone else is talking.
Answer:
"Without innovations in food production, the factories could not have grown so quickly. The trend quickened after 1860 and continued throughout the 21st century as well."
Explanation:
Because in the previous sentence it already stated the same thing. (PS I probably got this wrong)
I think this sentence would be better if we put an additional 'the' before the word 'students'
So the sentence will become :
it could be dangerous to carelessly teach grammar to the students
hope this helps
