Final answer:
The best definition of product features is specific design characteristics that allow a product to perform certain tasks, encompassing both physical and intangible aspects that differentiate a product.
Step-by-step explanation:
The best definition of product features is c) Specific design characteristics that allow a product to perform certain tasks. Product features refer to particular attributes or aspects of a product that enable it to accomplish what it's designed for. These can range from physical aspects of the product, like an unbreakable bottle or nonstick surface, to intangible aspects such as a reputation for high quality or provisions like free delivery. Product differentiation can occur based on features that distinguish one product from another in terms of design, quality, or additional services offered. This differentiation could be related to how the product is perceived in the mind of the consumer, often influenced by advertising and brand reputation.