Answer:
A. the assembly line
Step-by-step explanation:
The assembly line was an invention by Henry Ford that aimed to reduce the time that a certain product, in this case a car was produced, this increased the productivity of his company and increased the profit, the assembly line is basically a moving line were different workers did a repetitive task for long periods of time, putting thousands of bolts a day while other tightens them, and other worker puts the tires, or another part of the car.