Which figure is credited with popularizing mass production through the assembly line?

• A. Thomas Edison
• B. Nikola Tesla
• C. Eli Whitney
• D. Henry Ford

Answer: (D)

Mass production through an assembly line hinges on organizing work so that each worker repeats a simple, specialized task as parts move along a conveyer. Henry Ford popularized this approach by introducing a moving assembly line in his factories, especially for the Model T. This setup slashed the time needed to assemble a car, significantly lowered costs, and made cars affordable for a broad range of people. That impact is why Ford is the figure most credited with popularizing the assembly-line method in mass production.

The other figures made important contributions in different areas: Edison advanced electrical invention and innovation, Tesla contributed to electrical power systems and other technologies, and Eli Whitney introduced interchangeable parts that helped standardize manufacturing, but they did not popularize the assembly-line production method itself.