The number of cars produced has decreased. The need for custom manufacturing has increased. The efficiency of manufacturing plants has increased. The number of countries producing cars has decreased.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Which of the following statements best describes how the use of interchangeable parts has affected car manufacturing?
Possibilities:
- The number of cars produced has decreased.
- The need for custom manufacturing has increased.
- The efficiency of manufacturing plants has increased.
- The number of countries producing cars has decreased.

The efficiency of manufacturing plants has increased.