If by comparing Google Ads data with offline data you find a difference in the number of sign-ups for ads between the two sources, and you believe the issue lies with when a conversion was counted, what's the likely source of that data discrepancy?

The correct answer highlights a common discrepancy source: attribution modeling. Google Ads, by default, often attributes conversions to the date and time of the ad click that initiated the conversion path, not the actual date and time the conversion occurred. Other data sources, especially offline systems, typically record conversions based on when they actually happened. This difference in conversion date reporting can lead to varying sign-up counts when comparing data from different systems. The other options are incorrect because they misrepresent how Google Ads reports data (e.g., reporting clicks against events, views against device types, or conversions against unique IDs of clicks).