Answer:
1950
Explanation:
ocean liner were the primary mode of intercontinental travel fot over a century from the mid-19th century until they began to be supplanted by air liner in 1950's
Answer: open new markets.
Explanation:
The greatest priority of western railroad development as illustrated above was to open new markets.
Connecting the coasts made exportation easier to the Eastern markets. The development of the railroad also brought about new economic opportunities and new territories were also easily accessible.
The answer is c because this answer is the only one that makes sense