'Naturalis Historia' (Natural History), a Latin encyclopaedia that describes India's trade with Rome, was written by:

"Naturalis Historia" (Natural History), a large Latin encyclopaedia, was written by the Roman scholar Pliny the Elder (Gaius Plinius Secundus) in the 1st century CE.

About Pliny the Elder:

• He was born in 23 CE in northern Italy.
• He was a Roman soldier, administrator, naval commander and scholar.
• He died in 79 CE, during the eruption of Mount Vesuvius, while trying to rescue people and observe the eruption near Pompeii.

About the Natural History:

• It was completed around 77 CE, and has 37 books.
• It covers astronomy, geography, zoology, botany, medicine, minerals, art and many other subjects.
• It is one of the largest surviving works from the Roman empire.

Its references to India:

• Pliny described India's geography, peoples, animals, plants and products.
• He described the sea route to India using the monsoon winds, and the ports of the western coast, such as Muziris.
• He complained that India drained Rome of about 50 million sesterces every year, in exchange for luxury goods such as pepper, spices, pearls, precious stones, fine textiles and ivory.
• He mentioned that Indian goods were sold in Rome at a hundred times their original price.

NCERT on Indo-Roman trade:

• NCERT notes that the trade between India and the Roman empire was extensive in the early centuries CE.
• Large hoards of Roman gold and silver coins have been found in south India.

Other classical writers on India:

• Megasthenes: Greek ambassador at the court of Chandragupta Maurya; wrote "Indica".
• Strabo: Greek geographer (1st century BCE-1st century CE).
• "Periplus of the Erythraean Sea": an anonymous Greek guide to the ports and trade of the Indian Ocean (1st century CE).
• Ptolemy: Greek geographer (2nd century CE); wrote "Geography", listing many Indian places.
• Arrian: wrote about Alexander's campaigns and India.

Why not the other options?

• ✗Ptolemy, Strabo and Megasthenes wrote other works.