It shows that there are more sources for the reader to read, and it also is strong supporting evidence for the main idea.
The correct answer is D. Write several ads and see which one performs the best
Explanation:
An advertisement or ad refers to a material that aims at persuading the audience to take some action or buy some product or service. Because of this, text ad or the written section of an advertisement as well as any other elements on it need to be carefully planned and written based on the features of the possible audience and using persuasion techniques.
Considering this is not a simple task one of the best and most effective practice is to write different ad text and also design different elements in advertisements and then in a similar way to an experiment determine which one is more appropriate for the audience. In this way, it is guaranteed only the best advertise and the best text ad will be chosen. Therefore, the best practice for writing an effective text ad is "write several ads and see which one performs the best". Also, other such as passive language, talk about yourself should not be used in a text ad.
An epiphany is the realization that your past way of thinking was flawed. hope this helps :3