"Beyond MVC Quiz" - no correct answers to video questions..[RESOLVED]

Link to quiz: https://teamtreehouse.com/library/ios-design-patterns/mvc/review-beyond-mvc

The four possible answers are:

• Ordinary message passing method calls)

• Notifications

• Delegation

• KVO

I have gone thru the quiz dozens of times.

I can get all the other five non-video questions right,

but that's not enough to pass.

So I decided to be systematic..

On the two quiz questions with video attached,

I went thru one time and answered KVO to both (and both were wrong).

I went thru a second time and answered Notifications to both (and both were wrong).

I went thru a third time and answered Delegation to both (and both were wrong).

I went thru a fourth time and answered "Ordinary message passing (method calls)" to both (and both were wrong).

Is it just me (and my computer) --and maybe I should be calling Treehouse support?

...or is something wrong with this quiz that there is no answer that comes as correct (???)

for either of the video quiz questions.

Is anyone else running into this strangeness?

Update - 02.08.2016 - I tried it again today (Monday) and something changed because I was able to get through it with the answers Alexey and Jose suggested.

I noticed also that the answer for the Pong question (whether MVC was a good choice) had changed from accepting "True" as the right answer to accepting "False" as they right answer (which agrees more with the video).

Who knows when the update got done over the weekend --maybe late Sunday,

but at least now I got my points/badges for the course.