Answer:
Option C, fall which by itself would decrease aggregate demand, is the right answer.
Step-by-step explanation:
Option C is correct because the reduction in the confidence level in U.S financial institutions will decrease the U.S net export. Moreover, if the foreigner feels insecure about the U.S bonds then this insecurity will induce them to demand less. Therefore, when the net export decreases the aggregate demand will also fall. Thus we can say option C is right.