How did the us plan on upholding the marine doctrine?

a. through threats to foreign nations

b. through negotiations

c. with force if necessary

d. with from other nations

question as stated in comment

why did the chinese require the portuguese to pay for goods in gold and silver when trading?

choices

portuguese goods were less valuable than chinese goods.

the chinese already had a surplus of portuguese goods.

the imperial government wanted to stockpile gold and silver.

portuguese and chinese currencies were not exchangeable.

this a history q n in ancient time, theres no money exchange. so ans is portuguese and chinese currencies were not exchangeable.

this link can you answer the question.