The answer is the light bulb.
Answer:
The railroad boom began in 1862, when president Abraham Lincoln signed the Pacific Railway Act. This act offered two companies land along its right of way in order to speed progress. What railroad had a more difficult time with building their rail line due to the Rocky Mountains.
Explanation:
Group? Maybe?
I hope I helped:/
I am 100% sure its B. Phoenician got it correct on the exam.
B) A bombing in Berlin, Germany.
Hope that helps, Good luck! (: