What is the largest selling product derived from sheep?

Wool is recognized as the largest selling product derived from sheep due to its extensive use in textiles and various industries. Sheep are primarily raised for wool production, and it is a significant component of the global textile market. The versatility of wool, which can be spun into yarn and used for a wide range of clothing and home goods, contributes to its high demand.

While meat is also an important product derived from sheep and has considerable market value, it typically does not match the global scale and economic impact of wool. Leather and milk are lesser-known products in the context of sheep farming. Wool holds a notable position in terms of both production volume and economic importance, making it the correct answer in this question.