The correct answer to this open question is the following.
Although there are no options attached, we can say the following.
We can say that the people in the post-Mauryan periods had trade relations with distant lands because they were people dedicated to farming the land and developed good agriculture techniques that made them produce good cash crops that were traded to faraway places like Europe.
These long-distance trade routes served also to trade crafts and pieces of art. South Indian people could create routes by land through the river valleys. Post-Mauryan people learn how to navigate the Arabian Sea to create navigation routes to other distant places.
Alcids (or auks) fill a similar ecological niche in the northern hemisphere as penguins do in the southern hemisphere, except alcids can fly — and can fly long distances. The top photo is of a mixed group of Rhinoceros Auklets and Common Murres in flight over Monterey Bay in February, some having flown thousands of miles from Alaska to reach that rich pelagic wintering locale.
To quote Nettleship (1996), alcids are "a highly specialized and ecologically diverse group of marine, wing-propelled pursuit-diving birds." Many live at high northern latitudes — like this group of Atlantic Puffins and Razorbills (left) on Machias Seal Island, Canada — where their fat well-insulated bodies and comical appearances add to the feeling that they recall "northern penguins." Like penguins, though, some species reach tropical latitudes.
