With US$493.78 billion in assets as of June 30, Banco do Brasil SA, is the region's largest bank by almost US$100 billion, followed by Itaú Unibanco Holding SA with US$396.12 billion in assets.
Refer to the input text as context and select the correct relationship between 'Unibanco' and 'bank' from the available options.
Options: original broadcaster, creator, product/material produced, parent organization