Mary feels confident managing Google Search campaigns and is interested in extending her marketing reach with the help of Google Display ads. She’s trying to decide whether to create a Standard Display campaign or a Smart Display campaign. Why would Mary choose Standard Display campaigns over Smart Display campaigns?

She wants full control over all aspects of her Display campaigns is correct.

Explanation:

With the help of Google Display ads, she feels comfortable in running Search campaigns and seems to be engaged in expanding its marketing scope. She is difficult to determine whether it will build a regular show campaign or a campaign for smart displays. And she opts for full control of all facets of her Show campaigns.