I didn’t understand ______, so I raised my hand to ask.

A．what my teacher says

B．what does my teacher say

C．what my teacher said

D．what did my teacher say

投资者预期某种金融资产价格将要上涨时通常会买入（）

A．美式期权

B．欧式期权

C．看跌期权

D．看涨期权