Answer:
A.
Step-by-step explanation:
"Reaching the Top" is a short drama written by Ken Ruble. The drama reveals how Yu's character develops over the period of drama.
At the beginning of the drama, one can see that Yu is troubled with the difficulty of hiking. The evidence of this is when he asks Lian, catching his breath, that how much farther the top of the mountain is.
Therefore, the correct answer is option A.