The role of a functional manager is to perform various management roles within an administrative or functional area of the business, such as human resources, finance, accounting, or procurement. He is assigned his own permanent staff to carry out the ongoing work. He should have a clear directive to manage all tasks within his functional area of responsibility. Answer option D is incorrect. A project manager is an expert in the field of project management. He is responsible for the entire project from inception to completion. The project manager leads the team and helps negotiate the multiple relationships within any project whether with clients, team members, firm principals or any variety of partners and functions as the hub of a project. Answer option A is incorrect. Seller is also known as a vendor, supplier or contractor. They are external company's elements that enter into a contractual agreement to provide components or services necessary for the project. Answer option B is incorrect. The role of operations manager is to perform various management roles in a core business area, such as research and development, design, manufacturing, provisioning, testing, or maintenance. The operations manager directly deals with constructing and maintaining the saleable products or services of the enterprise.