Refer to the input text as context and select the correct relationship between 'Altria' and 'tobacco' from the available options.
Options: subsidiary, legal form, product/material produced, stock exchange

The most significant news was that SABMiller's largest shareholder Altria Group, which is a holding company for tobacco companies such as Marlboro, had apparently been approached by ABI in the week before the bid proposal was released.
product/material produced