Frank runs a scuba-diving business that offers lessons and sells scuba-diving equipment. Frank wants to engage with users who are researching scuba-diving lessons. Which marketing objective should Frank choose when creating his Display campaign?

influence consideration

Explanation:

Influence consideration is a marketing objective that is targeted toward a group of potential customers who already aware of your product, but still not sure whether your product is better than your competitor's. So they're pretty much weighing their options.

In the example above, The target is the users who are researching scuba-diving lessons. The interest for the product is already exist. In order to attract the attention toward his business, Frank need to create a campaign that offer more value compared to the competitors. (probably can be done by giving a couple of preview about what the lesson would look like or offering money back guarantee)