The options are:
a). Nebergall is an armchair Mars enthusiast with a career as a business analyst.
b). Nebergall argues convincingly that Mars is the last, best hope for the survival of humanity.
c). I think that Nebergall is a brilliant scientist who needs to be recognized.
d). Nebergall avoids using pathos in his essay.
Answer:
b). Nebergall argues convincingly that Mars is the last, best hope for the survival of humanity.
Explanation:
The introduction of any literary work primarily aims to clarify the topic to the readers, state its importance, thesis, grab readers' interest and attention, and highlight the key focus that the author will throw light upon.
In the given essay, the second option most adequately enhances the introduction as it clearly states the key argument of the author that how credibly 'Mars is the last yet most effective alternate for human survival.' This would not only inform the readers about the author's viewpoint but also capture their interest. The description of the use of the data establishes the logical validity of the claim and supports the author's claim. Thus, option b is the correct answer.