Under modern stakeholder theory, Starbucks stakeholders would include:

The employees, because their jobs depend on the success of the company.

The shareholders, because the board of directors has a duty to maximize the return on their investments.

The shareholders, employees, and customers, vendors, suppliers, and people who grow and harvest the coffee beans used in Starbucks coffee.

The managers, because of their duty to guide the successful operations of the company.

$a,b,$ and $c.$