Refer to the input text as context and select the correct relationship between 'Mattel' and 'doll' from the available options.
Options: employer, founded by, industry, product/material produced

Mattel Swings to a Loss as Barbie Sales Drop Sixth straight quarter of declines for toy maker’s iconic doll By Cassandra Jaramillo July 16, 2015 4:41 p.m.
product/material produced