pls? What type of discovery might help scholars decipher Indus Valley Civilization writing?

Which fact would this be, and how might you verify the truth?

The primary goal of the abolitionist movement was to a) immediately emancipate or free all enslaved people. b) allow the gradual release of enslaved people. c) end the importation of enslaved people from africa. d) make mandatory the education of all enslaved people.

The 20th amendment, also called the lame duck amendment, decreased the amount of time between the presidential election and the inaugration of the new president. what are the advancements that allowed for this amendment?