This is the correct answer because a partial copy sandbox can provide a subset of production data that is refreshed every 5 days. This way, the user acceptance and functional teams can test independently in isolation, and on current production data that was modified within the last week. A developer pro sandbox has a limited data storage and cannot store enough data for testing. A developer sandbox has no data and is only suitable for development and testing of code. A full sandbox can provide a complete copy of production data, but it can only be refreshed every 29 days, which may not meet the requirement of testing on data that was modified within the last week.