The writer directly tells the reader to use their skills as a careful observer when they go to the show to:
An observer refers to a person who observes or monitors something. The writer directly tells the reader to use their skills as a careful observer to tell them that understanding the drawings at the show might be difficult.
Also, the readers while going to the show should try to find mistakes in the drawings by their observations.
Hence the correct options are a and e.
Learn more about an observer here:
https://brainly.com/question/4351783