宾语从句 which one 和what 后跟不定式的区别

题目

宾语从句 which one 和what 后跟不定式的区别
I've never seen so many beautiful pictures.I don't know _____.
A.which one to take
B.what to take
哪个正确,

答案

选择which one,因为what表示的是什么,前面已经提到了是花,已经知道是什么东西了,应该是我不知道选择哪个,