Option C is correct because it ensures the finance team has the necessary permissions to link a project to a billing account without granting them unnecessary privileges. The Billing Account User role allows them to access the billing account, while the Project Billing Manager role enables them to link projects to the billing account. This combination meets the requirement precisely. Options A and B are incorrect as they either do not provide the necessary permissions to link projects or incorrectly assign permissions to the engineering team. Option D is incorrect because it grants the engineering team permissions they should not have, contrary to the requirement.