Refer to the input text as context and select the correct relationship between 'Mattel' and 'doll' from the available options.
Options: business division, distributed by, product/material produced, chairperson

Mattel Inc. said Thursday it swung to a loss in its second quarter, though the toy maker posted a surprise profit on an adjusted basis, as sales in the iconic Barbie doll line declined for a sixth-straight quarter.
product/material produced