Answer:
The scientists who invented the V2 rocket and V1 flying bomb were used by NASA to build the rockets that sent us to the moon. To think that the greatest achievement of mankind was also built on the shoulders of its greatest atrocities. They also helped to create Intercontinental Ballistic Missiles, and a new age of Nuclear warfare.
Most likely the answer will be b because it is secondary.D could also be a choice but I recommend B
When he went to Milan, the Duke Sforza appointed him to be a military engineer where he had to design weapons and technological advancements that would help the duke gain warfare supremacy against enemies. He also built buildings and defenses, not just offensive weapons.