Option b is the correct answer. Ibn Battuta, the Moorish traveler, gave a detailed description of the postal system during the Sultanate period. He was amazed by the efficiency of the postal system in 14th-century India. Ibn Battuta noted that this system enabled merchants not only to send information and remit credit across long distances but also to dispatch goods required on short notice. In his account, Ibn Battuta mentioned two types of postal systems: the horse post and the foot post. The horse post utilized royal horses stationed at intervals of four miles. On the other hand, the foot post had three stations per mile, known as "dawa." The efficiency of this postal system was remarkable. For instance, it took around fifty days to travel from Sind to Delhi, yet news reports from spies would reach the Sultan within just five days through this well-organized postal network. Important Tips Travellers during Delhi Sultanate: Marco Polo from Italy Period of Travel: 1292-1316 AD Under Reign: Alauddin Khalji Ibn-e-Batuta from Morocco Period of Travel: 1333-1342 AD Under Reign: Mohammad Bin Tughlaq Abdur Razzak-Ambassador from Iran Period of Travel: 1442-1443 AD Under Reign (Ruler or Dynasty): Sikander Lodi