What was the continuous front​

The opposing armies in the west were so vast that they could be deployed across the entire European continent, forming a continuous front. Early in the war, the opposing armies engaged in mobile tactics in an effort to outflank each other, but were countered as opposing troops were brought in to extend their lines.

It's The opposing armies in the west were so vast that they could be deployed across the entire European continent, forming a continuous front. Early in the war, the opposing armies engaged in mobile tactics in an effort to outflank each other, but were countered as opposing troops were brought in to extend their lines.The Western Front was the main theatre of war during the First World War. Following the outbreak of war in August 1914, the German Army opened the Western Front by invading Luxembourg and Belgium, then gaining military control of important industrial regions in France.

Explanation:

answer; /// i believe that the correct answer is (divison of labor);

the fact that could also be added to column b is that during world war ii, specifically between the years 1941 and 1945, japan expanded its territory towards the indonesian territory in what was known later as part of the "pacific war". in that time, japan could conquer the philipines, singapore,   borneo, central java, malang, cebu, sumatra and various other islands of the area, therefore expanding its territory for a brief period of time.