With the Dawn of the Industrial Revolution Came New Ways

With the dawn of the industrial revolution came new ways of using children in the workforce. Children were used predominantly because

A) they could work long hours without tiring like adults would.
B) they would do what their parents told them.
C) their smaller hands and bodies enabled them to do things adults could not.
D) their parents paid to have them employed so they wouldn't have to take care of them.