Wrong Answer In Dedicated Toefl 2 Session 1 - Reflection in Teaching

In the “Dedicated Toefl 2 Session 1” video - Reflection in Teaching’s passage summary question Greg has marked the answers as B, C & E
But in the official book the answers are B, D & E.
Can someone explain why is it D and not C?

cc @gregmat

Can you cross-check, I don’t have the TOEFL books with me anymore.

It’s possible I just made a mistake for this one – sorry about that!

if that’s the case then we can add a note about below the video!