Question

Why was Otto von Bismarck nicknamed the "Blood and Iron Chancellor"?

He suffered from an iron deficiency disease.

He received a disabling wound in battle.

He put political enemies into prison.

He preferred to use armed force.

Answer 1

Bismarck knew that war could accomplish his goals. He once remarked that things should be settled by “blood and iron”.
So your answer would be that he preferred to use armed force.

Answer 2

D - He preferred to use armed force.