"one day, as i scanned the sandy expanse of northern africa, i couldn't find any of the familiar landmarks-colorful outcroppings of rocks in chad, irrigated patches of the sahara. then i realized they were obscured by a huge dust storm, a cloud of sand that enveloped the continent from morocco to the sudan."

this quote from "single room, earth view" suggest what kind of tone?

a. awe
b. boredom
c. isolation
d. sorrow