Answer:
C, Brain drain
Step-by-step explanation:
What is brain drain? Brain drain according to Wikipedia is a problem described as the process in which a country loses its most educated and talented workers to other countries through migration. Negative effects include loss of tax revenues by the home country, and a loss of key health and education service professionals. A brain drain can result from turmoil within a nation, the existence of favorable professional opportunities in other countries, or from a desire to seek a higher standard of living. Johanna's brain drain came as a result of more favorable conditions in the U.S.