Why is World War I often considered a prime example of total war?

Question

Responses
A It was an industrial war.It was an industrial war.
B Propaganda was used effectively.
C It was fought only on one continent.
D Citizens were targeted during combat.

Answer 1

A It was an industrial war.
B Propaganda was used effectively.
D Citizens were targeted during combat.

These are the reasons why World War I is often considered a prime example of total war.