Brain drain is

Question $9$ options:

a$)$

an environment in which well$-$connected unscrupulous business people use corrupt political systems to their advantage in order to obtain preferential treatment from government.

b$)$

an environment in which property rights and contracts are respected and administered fairly and transparently, without favoritism

c$)$

tendency for the most highly talented people from developing countries to become educated and then move to an already wealthy country

d$)$

None of the above is true