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:

• 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 invented by Henry Ford.
• Option D: Henry Ford perfected the assembly - line production method. This mass - production technique significantly reduced the cost of manufacturing cars (e.g., the Model T), making automobiles more affordable for the general public.

Answer:

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