France and Germany doubled their armies, and Great Britain and Germany had the world’s largest and strongest navies because increased as countries realized they needed to have the most powerful military to protect and expand their empires.

A. militarism
B. alliances
C. nationalism
D. imperialsim

the american rail road was the most influential and useful transportation system developed in the 1800's with steam locomotives and in the very late 1800's and early 1900's diesel electric locomotives being used to transport goods and people around the newly expanded united states!

i think the answer is b.