Which invention from the industrial revolution was most important

Which of these resulted in an actual slow down or limiting of the u.s. and soviet nuclear arsenals?

The revolutions in latin america in the 19th century resulted in political independence from europe the end of slavery in each country the establishment of stable democracies social and economic equality for all

The transcontinental railroad runs from the to the i. north ii. south iii. east iv. west a. i and ii b. ii and iii. c. iii and iv d. ii and iv