The answer is D.
The battle of Gettysburg took place in nothern territory. General Robert Lee led the confederate army into Pennsylvania and brought the war directly into northern territory.
The Union army of the Potomac led by General Meade, met the confederate invasion near the Pennsylvania town of Gettysburg and what began as a chance encounter quickly turned into a desperate ferocious battle and on July 3rd, the battle turned against Lee and he opted to retreat.
I would go with 'Major sandstorms destroyed the crops' because the Indus Valley civilization most likely declined by something affecting the food.
Answer:
Factories, Mines, and Child Labor
The Industrial Revolution created a great deal of change in society.
One major change was the shift from work being done at home by
hand in cottage industries to work being done in factories. There
were harsh and unsafe working conditions in these early factories.
The machines posed a significant threat to workers’ lives. Even more
deadly was work performed in coal mines. Owners of mines and
factories had considerable control over the lives of laborers who
worked long hours for low pay. An average worker would work 14
hours a day, six days a week. Fearful of losing their jobs, workers
would typically not complain about the horrible conditions and low
pay. Owners realized that they could pay women and children less
than men. Child labor increased because it kept the costs of
production low and the profits high. As a result, the working class
lived in poverty, while the bosses who made up the middle class
grew wealthy.
Explanation:
Hope this helps :)