One consequence of increased migration is that anthropologists , collecting data in two or more locations

Anthropologists are more likely to conduct multi-sited ethnography because of increased migration.

Explanation:

Multi-sited ethnography entails the collection of ethnographic data and conducting fieldwork in two or more field sites. This is useful for doing work on migrant diasporas for example, where an anthropologist may be interested in studying the push and pull factors that lead migrants to leave their home countries and migrate abroad in search of better economic opportunities. Multi-sited ethnography also helps to understand the ties that people who migrate might keep with communities back home by sending remittances back to their families who stay in the home country.

your question is incomplete

explanation:

d. the polar jet stream   lies between the polar easterlies and trade winds should be your answer