Gail is a marketing manager who received a series of ads from her creative team. She wants to improve her ad content by using A/B testing. Which type of ads will Gail compare?

Ads with exposed groups, on the same message, and directed at the same audience.
Ads with unexposed groups, on the same budget, and directed at the same audience.
Ads used in brand lift, on the same channel, and directed at the same audience.
Ads used in identical ways, on the same channels, and directed at the same audience.