【开放英语4(英语II(2))-1162网上形考机考题库】 While I was in the university, I learned taking a photo, _____ is very useful now for me.

【开放英语4(英语II(2))-1162网上形考机考题库】 While I was in the university, I learned taking a photo, _____ is very useful now for me.
A. it
B. which
C. that
D. what