Zhang wants to prevent their ads from appearing on irrelevant shopping results and product detail pages. Which targeting method should they use to designate products where the ad should not be served.

The correct answer is "Negative product targeting" because this method allows advertisers like Zhang to specifically exclude certain products from being targeted by their ads. By using negative product targeting, Zhang can prevent their ads from appearing on irrelevant shopping results or product detail pages, ensuring that the ads are only shown for relevant products. This targeting option is especially useful for filtering out low-performing or unrelated products, which helps to optimize the ad spend and increase the likelihood of reaching the most relevant customers. In contrast, audience targeting focuses on demographics and behaviors, and automatic targeting relies on the platform's algorithm to determine where ads should appear, without the level of control provided by negative product targeting.