What hardship did both central pacific and union pacific workers face? (a)attacks from american indians (b)blasting through the sierra nevada (c)extreme weather conditions (d)losing workers to the gold rush

Extreme weather conditions.

The Central Pacific Railroad was a cargo and passenger train company that had operations between California and Utah in the 1860s.  

The Union Pacific Railroad is a similar company set up in 1862, that has country wide operations covering Chicago, Illinois to the Pacific coast. The Central Pacific Railroad, later on became part of the Union Pacific

c. extreme weather conditions

a phrase from a poem by ralph waldo emerson about the battle of lexington and concord. emerson's words read, “here once the embattled farmers stood / and fired the shot heard round the world.”