A clothing company wants to know how many shoppers who first saw their ad on a mobile app ended up purchasing clothing by using their personal tablet. What type of Display & Video 360 measurement should you use to access that information?

Cross-environment conversions track user actions across different devices and environments (e.g., mobile app to tablet). This directly addresses the scenario of a user seeing an ad on a mobile app and converting on a tablet. Conversion tracking is a general term for measuring conversions but doesn't specifically highlight the cross-device aspect. Same-device measurement would only track conversions on the same device where the ad was seen, which isn't the case here. Open Measurement SDK is used for verifying ad viewability and performance within mobile apps, not for tracking cross-device conversions.