What is the relationship between American Girl and doll in the context of the input sentence. Choose an answer from: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

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.

Answer: product_or_material_produced