Which of the following growth levers can only be used by brand owners who use Fulfillment by Amazon(FBA)?

Virtual Bundles allow brand owners to create product bundles from two to five complementary FBA products. This feature is exclusive to FBA sellers because Amazon handles the fulfillment of the individual items within the bundle, ensuring they are shipped together as a single unit. Amazon Attribution, on the other hand, is a measurement solution that helps advertisers understand the impact of their non-Amazon marketing channels. It is available to all sellers, regardless of their fulfillment method (FBA or FBM), as it focuses on tracking external traffic to Amazon listings, not on fulfillment logistics.