【单选题】

The reference to Mount Everest in Para. 9 differs from that in para. 10 in that the first reference is an example of ______.
A．(A) something easy to do, whereas the second reference is an example of something difficult

B．(B) goals that have been achieved in the past, whereas the second reference is an example of goals to be considered
C．(C) a tall mountain, whereas the second reference is an example of the tallest mountain
D．(D) something outlandish, whereas the second reference is an example of a goal worth pursuing