PLS HELP GUYS!! THIS IS WORTH 160 PTS!!!(PLUS I WILL MARK BRAINIEST WHEN SOMEONE ANSWERS CORRECTLY FIRST)

Australia exports more goods to China than any other country it trades with. These goods include such things as iron ore, coal, crude petroleum, and wool. In turn, Australia imports goods like computers, cars, and refined petroleum from China. This is an example of how _______ promotes trade.


A
a quota

B
productivity

C
a tariff

D
specialization