Kings, especially in early European countries like France or Britain could order around the peasant of a nobleman, although this rarely happened because of the respect between Noblemen and Kings. This is also because Kings hold a higher power than Nobleman.
The berlin airlift occured because Stalin put forth the berlin wall. this action divided the east berliners from the west (brain drain). the soviets were mad that their "side" was being exposed to the capitalistic side of Germany which belonged to NATO. so then they decided that it was over for the berlin wall.
Hello!
The correct answer ro your question is: B. It needed ports that could be used year round.
I really hope you found this helpful! :)