What Best Defines Virtual Expatriates

What best defines virtual expatriates?

A) They stay and work abroad for a short period of one to two months and then return to their home country.
B) They work in a foreign culture and blend to such an extent that they may more closely resemble a local than an expatriate.
C) They work abroad in one country after another for the greater part of their career.
D) They are expatriates from their own countries working for a foreign company in a third country.
E) They manage operations in foreign countries but do not move there.