Im stuck between a and d its like they both seem right, sorry.
I think it's the telephone because it allows people to communicate better and customers or workers don't have to walk up to everyone and disturb them. You may elaborate more on this with your own opinion
The best description
is "<span>A network of roads helped him to rule an empire".
Sapa Inca also known as Sapa Inka or Apu was the King of the Kingdom of Cusco,
later to Inca Empire. Incan Empire was the largest known empire in pre-Colombian America and their network of roads is one of the major reasons for that great
rule.</span>
