ASAP answer for stars, brainist, thank you and points, You can answer with proof if you want!

The value of the next best alternative given up is called ?

Plz me i need a good grade ! 10 government is a government system where all citizens that choose to vote have a say in their government? a: communist b: democratic c: autocratic d: theocracy

Which groups of people most directly benefited from song innovations in the song dynasty‘s open border policy?