Azure Data Box is the correct choice because it is designed for offline bulk data transfer when large amounts of data need to be moved and network conditions are not favorable for online data transfer methods. Azure Migrate is an online migration service that provides guidance across the migration lifecycle but would not be suitable here because of the limited and unreliable internet connectivity. While Azure Migrate might use Azure Data Box as part of a migration strategy, the direct question here is about the tool specifically suited for transferring the data under given network constraints.