Final answer:
The Persians advanced communication in their empire by building roads and creating an efficient postal service, featuring couriers on horseback who could swiftly deliver messages across large distances. The Royal Road was instrumental in this, facilitating rapid and reliable communication vital for empire governance.
Step-by-step explanation:
The Persians improved communication throughout their vast empire by building an extensive network of roads and inventing a postal service, as rightly noted by B - they built roads and invented a postal service. This sophisticated system relied on couriers who traveled along the Royal Road, a crucial highway link that extended from Anatolia to Susa. Couriers could cover 1,600 miles in a week by horseback, with horses and riders stationed at regular intervals to ensure the swift relay of messages.
The Persian postal system was an impressive feat and vital for maintaining efficient administration over such a large empire. Stations were strategically placed every 20 miles or so, where couriers would switch horses and continue to the next, ensuring that messages could move approximately 200 miles in a single day. This system helped the Persians standardize laws, issue regular coinage, and communicate efficiently using several languages with their subjects, as well as maintaining security and efficiency along major trade routes.
Herodotus, the ancient Greek historian, provides a detailed description of the courier system, famously stating that not even snow, rain, heat, nor darkness would stop these couriers from completing their appointed rounds swiftly. This commitment to rapid and reliable communication was so admired that it inspired the chief architect for the Eighth Avenue post office in New York City to select Herodotus' description as a motto, encapsulating the spirit of the historic postal service.