Which of the following actions is categorized as "Peddling"?

Peddling refers specifically to the act of selling goods or merchandise, particularly in a manner that is not associated with a permanent retail establishment. In this context, selling items on the sidewalk is a prime example of peddling because it involves offering goods directly to the public in a public space, typically without a fixed location.

Peddlers often operate in transient ways, moving from place to place to sell their products. This is distinct from running a legitimate business, which usually implies operating from a stable storefront or having a formalized structure for sales. Distributing flyers is an act of promoting or advertising, not selling, and conducting market research involves gathering information rather than trading in goods. Therefore, the first choice accurately represents the definition of peddling, aligning with the characteristics of selling items in a street or open area.