What action shortens a product line's depth?

Removing a product from a product line directly shortens its depth. Product depth refers to the number of variants or items within a specific product category offered by a company. When a product is removed, it reduces the variety available to consumers in that category, thereby decreasing the overall depth of the product line. This action may be taken for various reasons, such as poor sales performance, changes in consumer preferences, or the desire to streamline offerings to focus on more successful products.

Introducing a new flavor would actually increase depth by adding another variant to the product line. Enhancing product packaging does not affect the number of items in a line, and expanding distribution relates more to availability rather than the number of products themselves.