Final answer:
Operations managers are responsible for a range of activities including inventory management, product and process design, supplier relationship management, and quality assessment and improvement; thus, all the listed options fall under their responsibilities.
Step-by-step explanation:
The activities that fall under the responsibility of operations managers are quite broad and encompass many tasks that are crucial for the efficient functioning of a firm. This includes a. Inventory management, ensuring that the right amount of stock is available to meet demand without excessive surplus; b. Product and process design, which involves developing new products and refining existing ones, as well as setting up efficient production processes; c. Supplier relationship management, which is about establishing and maintaining good relationships with the suppliers that provide the materials necessary for production; and d. Quality assessment and improvement, which focuses on maintaining high-quality standards for products and processes.
Therefore, the answer to the student's question is e. All of these activities.