Unlike its predecessor, World War II featured large scale civilian casualties. Which of these BEST explains why this was the case?

Question

Responses
A Aircraft were used on a larger scale.Aircraft were used on a larger scale.
B Fewer military targets were available.Fewer military targets were available.
C International law had prohibited such actions.International law had prohibited such actions.
D Civilians often protested near the front lines.

Answer 1

A Aircraft were used on a larger scale.