Answer:
the cell phone from star trek
Explanation:
In star trek they use a device called a communicator which gave the idea of creating a cell phone
A. Greatly reduced the assembly time for each car.
I think you could pick both B and D in this situation. You didn't include the passage so I have nothing to go on here except my little knowledge of the story from when I read it.
Answer: Are we suppose to edit this writing or what?
Explanation: I am confused.