The correct answer is D. Environmental issues following a natural disaster
Step-by-step explanation:
In writing, including fictional and non-fictional texts it is common the author explores multiple themes, which are ideas or beliefs related to the content of the text the author wants to convey to the audience, although they might not be explicitly stated, because of this themes are often referred as underlying ideas and are usually linked to aspects of human life. Because of this, it is common texts that have similar content share common themes.
For example, in the case presented a text related to the Hurricane Katrina and one of the 9/11 might share common themes as they both were situations that had a great impact in the U.S., implied a situation of danger and required from strategies to respond to the emergency. However, Hurricane Katrina was a natural disaster and the 9/11 was not, and therefore themes related to this aspect might be different in these texts. Considering this, the theme tath you could find in Hurricane Katrina but not in a text responding to 9/11 is "environmental issues following a natural disaster".