What Is the Difference Between an "Immigrant" and a "Refugee

What is the difference between an "immigrant" and a "refugee"?

A) Anyone who moves is an immigrant while only those fleeing a war or a war zone are refugees.
B) An immigrant is a mover who moves from one country to another voluntarily while a refugee is a mover who voluntarily moves from one country to another due to persecution, threat of violence or deprivation.
C) A refugee is an immigrant who moves to a nearby country where war is not actively being fought.
D) An immigrant is a mover who moves from one country to another voluntarily while a refugee is a mover who involuntarily moves from one country to another due to persecution, threat of violence or deprivation.
E) There is no difference between an immigrant and a refugee.