What’s an example of a managed placement for a TrueView in-stream ad?

A) A website on the Display Network
B) A specific YouTube video
C) All of the listed answers are correct
D) A YouTube channel

The correct answer is:

C) All of the listed answers are correct

Explanation: It comes under placement targeting. You can target YouTube channels, YouTube Videos, Website on the Display Network and Apps on the Display Network.

Read more here: https://support.google.com/adwords/answer/2454017?hl=en