He argues that investors are not only sending a message to Glencore chief executive Ivan Glasenberg about the need for a less leveraged balance sheet, they are also sending a message to BHP Billiton and Rio Tinto about their unsustainable dividend policies.
Analyze the relationship between 'Ivan Glasenberg' and 'Glencore' within the context of the input sentence.
Options: owner of, publisher, brand, business division