Probably the invention of Papyrus (paper)
The third Reich is the correct answer
I think it is B, I hope it is help.
There are alot of factors that make it hard for archeologist and historians to search about the indus valley.the most highlighted factors are the enigmatic nature of Indus valley civilization means there is no clear connection to any continuous literary traditions.they have a much harder time imagining the life of Mohenjo-Daro because there isn't any reliable information about the culture of it. the fact that they cannot read the language(s) of the Indus valley means a lot!
I am not entirely sure about this one. But I believe that the "Emancipation Manifesto" signed by Czar Alexander II gave serfs land, or at least gave them the freedom to do what they wanted, like buying that said land.
No freedom of religion, or elections was yet to be had in Russia.