The best analysis of how migration can change culture from the provided options is:
Migration can spread cultural ideas to destination regions, but in recent eras it has had more of an effect on source regions.
This option acknowledges that while migration introduces new cultural elements to destination areas, it can also significantly influence the culture of the source regions, especially as migrants may maintain their cultural practices and ideologies, share them with others, or even lead to changes through remittances, communication, and return visits. This reflects a more nuanced understanding of the dynamic impacts of migration on both source and destination cultures.