Which option best describes a Product Line?

A product line is best described as a set of related products that address similar needs or problems for consumers. This means that the products within a product line are often designed to complement each other or fulfill a particular purpose, typically targeting the same customer segment. For instance, a company that offers different types of toothpaste with varying features (such as whitening, sensitivity protection, or fresh breath) is creating a product line that caters to the related needs of dental care among consumers.

In contrast, the other options do not accurately define a product line. A variety of unrelated products refers to a portfolio that includes items across different categories, lacking the cohesive connection that characterizes a product line. The overall number of products a company sells describes the breadth of a company's product range but does not indicate the relationships among those products. Finally, a single unique item offered by a brand describes a solitary product rather than a collection of related items that make up a product line. Thus, the definition provided in the correct answer captures the essence of a product line effectively.