Question

The _______ was not a change that occurred in america in the 1920's.

Answer 1

The steam locomotive was not a change that occurred in America in the 1920's.
This is because this type of locomotive was first operated in 1804 by Richard Trevithick in America. In 1801, he had made the road locomotive. 
The first one that actually carried passengers on a public rail line was Locomotion n°1 in 1825.

Answer 2

It's D, the steam locomotive was invented in the 1800s and was used for trains to send goods around quicker.