What is the relationship between 'American Girl' and 'doll' in the context of the input sentence.
Options: publisher, chief executive officer, product/material produced, manufacturer

The Maryellen doll and related products will be available August 27, 2015 at americangirl.com ; at all American Girl retail locations nationwide; through American Girl's catalogue; at American Girl specialty boutiques at select Indigo™ and Chapters™ locations in Canada; and at El Palacio de Hierro in Mexico City.
product/material produced