Question

how did henry ford contribute to changes in transportation in the early 20th century?
a ford perfected the interchangeable tire, making road travel easier.
b ford invented the first car and it quickly became the number one choice for transportation.
c ford invented the electric motor, thus allowing cars to travel over longer distances across country.
d ford perfected the assembly line, driving the cost of cars down, thus making them affordable to most people.

Explanation:

Henry Ford is known for perfecting the assembly - line production method. This innovation significantly reduced the cost of manufacturing cars. By using the assembly line, production efficiency increased, and the price of cars became more affordable for the general public.

• Option A: The interchangeable tire was not Henry Ford's main contribution.
• Option B: The first car was not invented by Henry Ford. Karl Benz is credited with inventing the first practical automobile.
• Option C: The electric motor was not Henry Ford's invention.
• Option D: This is correct as Ford's assembly - line method made cars more affordable.

Answer:

D. Ford perfected the assembly line, driving the cost of cars down, thus making them affordable to most people.