They used Maginot Line. The Maginot Line was built to fulfill several purposes: To prevent a German surprise attack. ... To push Germany into an effort to circumvent via Switzerland or Belgium, and allow France to fight the next war off French soil to avoid a repeat of 1914–1918. To be used as a basis for a counter-offensive.
To protect Catholics after England fell under Puritan rule
a. right of access
none of the others really work imo
B. the Folsom culture was the first to arrive in Oklahoma. Hope this helps