The correct answer is D. Cars were easier to repair if they broke down.
Step-by-step explanation:
The first car or vehicle that transported people was first designed in the 18th century based on on a steam-powered system, during this time and in subsequent decades each car was manufactured individually which means each car was manufactured individual by a group of works, this led to differences in the parts included in each car and the design which makes difficult to repair a car if there was any problem. However, this ended around the 20th century as cars began being manufactured in assembly lines and each car had the same parts as others, this did not only imply more cars were created in the same time but that cars were easier to repair.