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.
Take context from the input text and decide on the accurate relationship between 'Unibanco' and 'bank' from the options provided.
Options: product/material produced, parent organization, original broadcaster, creator