Hi there! Your answer is C.
"To her teacher that was late" throws you off, thinking "Oh. Had she been there before the teacher?" which is weird to explain but
It's not A. It says "project", so no.
It's not B. It says "Keiko handed HER castle project to HER teacher"
C. With the wordchoice used, it seems as if the teacher hadn't been there on time and had just shown up when Keiko handed her the project.
It's not D. It clearly says "Keiko handed her castle project to her teacher".
So yeah, your answer is C. Good luck!