Which One of the Following Defines the International Trade Multiplier

Which one of the following defines the international trade multiplier?

A) The amount that country A's income expands for each $1 increase in its exports
B) The amount by which international trade expands for each $1 expansion in exports of countryA
C) The amount that country B's imports grow for each $1 increase in country A's national income
D) A's income declines for each $1 increase in its imports
E) The amount that country B's national income rises (via an increase in exports to A) for each $1increase in country A's national income