Mattel's portfolio of best-selling brands includes Barbie ® , the most popular fashion doll ever produced, Hot Wheels ® , Monster High ® , American Girl ® , Thomas & Friends ® and Fisher-Price ® brands, including Little People ® and Power Wheels ® , MEGA ® Brands, including MEGA BLOKS ® and RoseArt ® , as well as a wide array of entertainment-inspired toy lines.
In the context of the input sentence, determine the relationship between 'American Girl' and 'doll'.
Options: product/material produced, founded by, original broadcaster, publisher