Under which circumstances is a Canada-based worker most likely to join the 'brain drain' and immigrate to the United States?

A: When the overall incidence of brain drain is higher, i.e. when many of her peers are doing it.

B: When she can get an immediate pay raise in the USA

C: Whenever the taxes that she faces in Canada are raised such that they exceed US taxes.

D: Whenever the discounted present value of her earnings in USA exceed the discounted present value in Canada

E: All of these above are possibilities