• Allows pulling preview sheets across all sizes without specifying the creative size in Step 5: Preview
• Easier to remove and add creative sizes in the feed
• Allows for less columns which reduces the dynamic response data sent from the ad server to the creative
• Lets dynamic campaigns scale as more creative sizes are added

Correct answers are: Easier to remove and add creative sizes in the feed, Allows for less columns which reduce the dynamic response data sent from the ad server to the creative, and Lets dynamic campaigns scale as more creative sizes are added

Explanation: Instead of creating separate columns to customize ad content for each creative size, you can filter by creative dimensions to reduce the number of columns in your feed. Using filer makes removing and add creative sizes in the feed easier. It allows for fewer columns which reduces the dynamic response data sent from the ad server to the creative.

Read more here: https://support.google.com/richmedia/answer/6023632