Answer:
A I think
Explanation: I don't know if this is right friend, But I least I tried:)
A) Magna Carta: limited power of rulers, trial by jury
Explanation:
This document expressed that the king was not above the law. It essentially prevented the king from exploiting his power (thus limited the power of rulers). Furthermore, the Magna Carta was the origin of the jury trial (which the US implemented into their government).
Sources:
https://www.parliament.uk/about/living-heritage/evolutionofparliament/originsofparliament/birthofparliament/overview/magnacarta/#:~:text=Magna%20Carta%20was%20issued%20in,as%20a%20power%20in%20itself
https://www.loc.gov/exhibits/magna-carta-muse-and-mentor/trial-by-jury.html#:~:text=The%20right%20to%20a%20trial,the%20creation%20of%20Magna%20Carta
The answer is B-the concept of a unicameral legislature