Your client wants to place image and video ads on a wide variety of websites so people will see them while browsing those sites. Which type of AdWords campaign would be best for that?
Search Network with Display opt-in
Search Network with YouTube Select
“Display Network only” campaigns are best if you’d like to show ads on websites and apps when your keywords are related to the sites’ content. You can’t use image and video ads on Search Network.
With a Display Network only campaign, your ads can show throughout the Google Display Network. This campaign type works by matching your ads — including text, image, rich media, and video ads — to websites and other placements, like YouTube and mobile apps, with content related to your targeting.
Read more here: https://support.google.com/partners/answer/6123890?hl=en