Answer:
The answer is C. link the advertisements to online promotions.
Step-by-step explanation:
Now lets take a look at it one by one and see why C is the answer.
As in option A, she can ask a few friends whether they've seen the ad or not, but their replies would not accurately show the success of the promotion strategy.
In Option B, it take some time to measure the results and the quarterly sales numbers can be influenced by many factors and may not reflect the impact of this specific promotional campaign.
Option D is irrelevant, Elise's company sales and the sales of the newspapers are not related. So we can not take this as an answer.
Option C however is very applicable. If you link the advertisements to online promotions, when those who read the news paper comes to check the online promotion, we can see how well has the ad performed based on the number of online enrollments of the readers.