About 6,000doctors in theprefix = st1 /Philippinesare studying to become nurses so they can find higher-paying jobs abroad, Health Secretary Francisco Duque says.   This was up from 2,000 doctors who studied to become nurses last year, Duque said.   The exodus of doctors and nurses had created a "threatening situation for our health care system" and a task force had been established to examine the potential impact, he said.   The team was working on a bill which would require doctors to practice in thePhilippinesfor at least three to four years before they were able to work abroad.   "I think the problem really is the migration of doctors. We have so many nurses now, more than enough to fill up(vacancies). But our doctors are leaving," Duque said.    A study by the University of thePhilippineshad found that between 2000to 2003 more than 50,000 Filipino nurses went abroad to work. A doctor working in a government hospital in thePhilippinesearns only about 25,000 pesos(446 dollars) a month. A  doctor could earn around 8,000dollars a month while working as a nurse overseas. Even lawyers, accountants and engineers are enrolling to brain as nurses.    Filipino nurses are in demand in Europe, the United States, the Middle East and even closer to home, such as in Singapore and Japan.    However, Health officials have warned the country faces a "medical apocalypse" if it continues to lose its health professionals to jobs abroad. The word "exodus" in Para3 can be probably explained by  _
return of lots of people leave of many people at one time fight between different people exchange of positions between people
Question: About 6,000doctors in theprefix = st1 /Philippinesare studying to become nurses so they can find higher-paying jobs abroad, Health Secretary Francisco Duque says.   This was up from 2,000 doctors who studied to become nurses last year, Duque said.   The exodus of doctors and nurses had created a "threatening situation for our health care system" and a task force had been established to examine the potential impact, he said.   The team was working on a bill which would require doctors to practice in thePhilippinesfor at least three to four years before they were able to work abroad.   "I think the problem really is the migration of doctors. We have so many nurses now, more than enough to fill up(vacancies). But our doctors are leaving," Duque said.    A study by the University of thePhilippineshad found that between 2000to 2003 more than 50,000 Filipino nurses went abroad to work. A doctor working in a government hospital in thePhilippinesearns only about 25,000 pesos(446 dollars) a month. A  doctor could earn around 8,000dollars a month while working as a nurse overseas. Even lawyers, accountants and engineers are enrolling to brain as nurses.    Filipino nurses are in demand in Europe, the United States, the Middle East and even closer to home, such as in Singapore and Japan.    However, Health officials have warned the country faces a "medical apocalypse" if it continues to lose its health professionals to jobs abroad. The word "exodus" in Para3 can be probably explained by  _
A. return of lots of people
B. leave of many people at one time
C. fight between different people
D. exchange of positions between people
Answer: