题目：【单选题】What’s the international capital flow or financial assets flow that mainly realized through international investment and international credit.
A、trade in factor services
B、trade in non-factor services
C、core service
D、additional service
题目：【单选题】What’s the international capital flow or financial assets flow that mainly realized through international investment and international credit.
A、trade in factor services
B、trade in non-factor services
C、core service
D、additional service