英語選擇—Which dress do you like best,Madam?

題目：

英語選擇—Which dress do you like best,Madam?
—Which dress do you like best,Madam?
—Sorry,I can’t decide______ now.
A.to buy which one B.buy which one
C.which one to buy D.which I should buy it
我知道選什麼,我只要問爲什麼A錯了,A好像沒有任何語法上的錯誤啊

解答：

這種結構一般是特殊疑問詞放在不定式之前的.例如最簡單的 I don't know what to do, i don't know where to go.特殊疑問詞放在不定式之前的,所以只能選C...