Answer:D)Conversion tracking
Step-by-step explanation:Conversion tracking is the tool that helps the user to know about the interaction of the ad given by him with customer. It helps in the tracking in the ways like calls from ads, call conversion importing,mobile website gaining the number of clicks etc.
Thus, Adam needs to use the conversion tracking tool which for driving the calls towards his store.He can track the effectiveness of the ad which drives the calls.
Other options given are incorrect because they cannot keep the record of the ads seen by the customer with the help of tracking. Thus the correct option is option(D).