Answer: I’m not sure but I would say c
Btw sorry if wrong
Explanation:
The ancient city of Harappa was considered to be advanced during its time due to multiple characteristics such as: the sheer size of the city (known today as urban); a large network of trade/commerce/transport technology and economy; accuracy of their measurement systems for length and mass; their use of measurements in architectural design, sewerage and drainage systems; innovative metallurgy techniques and manipulation of precious metals (lead, tin, bronze, copper).
Answer:
Most connections are on the East Coast.
"The United States has the largest rail transport network size of any country in the world. The nation's earliest railroads were built in the 1820s and 1830s, primarily in New England and the Mid-Atlantic region. The Baltimore and Ohio Railroad, chartered in 1827, was the nation's first common carrier railroad." per Wikiapedia.
Explanation:
https://en.wikipedia.org/wiki/Rail_transportation_in_the_United_States
Smaller wages, more energy, and smaller hands for minuscule work.