Answer:
B. Establishing contracts solely with countries where English is the major language.
Step-by-step explanation:
For some background information, the 20th century was from January 1, 1901, to December 31, 2000.
By using the same logic that would remove C and D from the answer list (that there are communications between countries with other major languages, due to linguistic advancement), we can reason that B is the answer.
Also to make sure, we can reason that A is also not the answer due to computers and the networking utilizing it were present in the 20th century, becoming prevalent in the 1970s.