Step 1 : Introduction to the question "Which of the following toy's distinctive smell is trademarked?"
...The iconic Play-Doh scent is officially recognized by the United States Patent and Trademark Office as a registered trademark of the brand. But how does one trademark a smell? Well, first of all, you must describe it and send it off to the office for an official government smell test by an examiner. Hasbro formally describes the trademarked scent as a “unique scent formed through the combination of a sweet, slightly musky, vanilla-like fragrance, with slight overtones of cherry, and the natural smell of a salted, wheat-based dough."