Which option led to the start of World War I? * O A declining spirit of nationalism within European countries
O Imperialistic efforts by European countries
O Agreement to decrease the size of military
O Refusal to form alliances with other countries

A or B.

Explanation:

The cause of World War 1 is still being debated today. The ones that are most popular, and with the most amount of compelling evidence to back it up, are choices A and B. Most accounts that were created were exaggerated, or just told half of the story, (because no one side is perfect and the other barbarians,) but we do know that it took place in Europe. The one sure-fire thing we know about World War 1 is that it started originally from threats, a royal family, and a grandiose murder. A-thank you, a-thank you very much (my best Elvis impression over the keyboard... oof)

answer: the time zones used to be whatever the local authority wanted them to be. one town might have 6am whenever the sun came up and another town had 6am 10 minutes later.  

the trains had a hard time when their orders said to be at a certain point at 6am.  

6am, but who's 6am.  

the railroads got together and set the time zones more or less along the longitude lines across the country.

explanation:

add me as friend then ill answer