What natural resource did the qin dynasty take advantage of to squash its enemies?

Iron

There was a rapid development of the iron industry in the Qin Dynasty. Qin Emperor Shihuang used iron as the natural resource to squash their enemies while trying to unify China. He set up officials in iron production increase income and strengthen the centralized power of the Qin Dynasty.

usually her father was the one that controlled it after the death of the husband

the answer for 3 is b and the answer for 4 is d