Respuesta :
We can say that the author opened the section with a question in order to provide us with icons that give visual cues about the topic: creating vaccines against the flu virus is a difficult, expensive process.
The answer is D. to provide readers with information for making predictions.
Explanation:
There is a reading technique in which we make predictions to get an idea of what we are going to read. In this case, the question gives us a clue for making predictions and understand better the text. In fact, the text says that there are several answers to the question, it means that we can do several predictions about it.