Why does the author most likely use the phrase “not unmindful” in the sentence?

A) to emphasize the vast size of the desert

(found on USA TestPrep)

Explanation:

  The author explains that the Sahara extends from the Red Sea in the east to the Atlantic Ocean in the west across the northern part of Africa.

the correct answer is the name of the author of the quotation appears at the text leading up to it   apex 2018

im not entirely sure what you're asking.