What new weapon made allied leaders worry about the cost of invading the japanese mainland

The correct answer is Kamikaze fighters, I just took the quiz. Notice it asks about the Allied leaders being worried, not the Axis leaders. The Allies had the atomic bomb, and the Kamikaze fighters attacks were becoming more common when the US was approaching the mainland. Kamikaze attacks started in 1944.

answer; the answer to the first question is (king james ii was replaced by his daughter mary and her dutch husband william of orange;

for many centuries there were important factors which the economies of the muslim empires developed increasingly. they applied economic procedures in production, investment, finance, taxation and property. they used to tax certain goods (for example: harvest), they charged interest on money lent, they signed contracts with merchants; they relied on a common currency, and they used checks as well as promissory notes. with the money collected by means of taxation, the government provided the needy with an income. in addition, trading networks covered huge distances, so far regions started to have contact and exchange goods. this trade network covered areas of asia, africa and europe.