What is one way to widen a Product Mix's width?

The correct answer highlights that widening a product mix's width involves adding a new product line to the existing portfolio. This action directly increases the variety of different product lines that a company offers, thereby expanding the breadth of its product mix. The width of a product mix refers to the number of different product lines that a company has available for sale. When a company introduces a new product line, it effectively increases its market presence by offering new categories of products that can attract different customer segments.

In contrast, increasing the number of products within a single line would enhance the depth of that specific line rather than the overall width of the product mix. Modifying existing products focuses on improving or changing features of products within the existing lines, which again does not expand the width. Reducing the number of unrelated product lines would actually narrow the width of the product mix, counteracting the goal of widening it. Thus, the correct choice accurately reflects how to successfully broaden the diversity of offerings a business can present to its customers.