Which is a best practice for a successful TrueView in-stream ad?

A) Add a frequency cap
B) All of the listed answers are correct
C) Include a strong call-to-action so the viewer knows what to do
D) Use at least 3 types of targeting to find out which performs best

The correct answer is:

C) Include a strong call-to-action so the viewer knows what to do

Explanation: Have a clear call-to-action within your ad, and select colors and fonts to match your brand.

Read more here: https://support.google.com/partners/answer/2375498?hl=en