PLEASE HELP ILL GIVE A CROWN! which of the following best describes mass production ?

A ) Cotton Gin allowed for more cotton to be processed at a cheaper price.
B ) Hand-made clocks from Germany were a one of a kind gift.
C ) Lowell Textile Mills had dormitories for their workers so they didn't need to leave the factory.
D ) Need for a large cheap labor source decreased with the invention of the steel plow.