Answer: (A) Look at engagement rate for targeting and focus on the methods with the highest view through rate
Step-by-step explanation:
TrueView video enables to post ads in social sites however it is paid by the sponsor only if the ad is viewed fully or in some cases it is viewed only upto 30s of the total size of the video.
So in order to have a larger viewer engagement it is necessary for it to focus on the methods which would garner it highest views.
So option A is correct.
Option B and c are not correct these options would not cater to the needs of the viewer.