I think it's D because it's the main thing
According to Churchill, the Battle of France lost because France could not handle the power of the armored columns.
The Battle of France, also known as the Fall of France, was the German invasion of France and the Low Countries during the Second World War.
The battle protracted from May 10th to June 25th in 1940 after the end of the period of waiting following the German invasion of Poland in 1939.
The Battle of France is considered even today as one of the most important battles of World War II in Europe.
Third one: Disapproval of....involvement. <span />
This sentence is grammatically correct but it is not adverb phrase it is Syntax
