你想要試用全通路出價功能，但某些類別僅限於離線使用。 建議採用的全通路出價功能設定是什麼？

Campaign-level omnichannel bidding is the correct setting because it allows you to apply the bidding strategy to specific campaigns that include both online and offline conversion goals. This is crucial when some product categories are exclusively offline, as it enables you to optimize bidding for the entire customer journey within those campaigns, encompassing both digital touchpoints and the final offline purchase. Account-level bidding would apply the strategy too broadly, potentially misallocating budget to campaigns without offline components. Ad group-level and ad-level settings are too granular; omnichannel bidding strategies are designed to optimize across a wider scope of conversions, which is best managed at the campaign level.