Answer:
C. The sound of the rasping breathing of her competitors trailed close behind her.
Step-by-step explanation:
Specific words are used usually to give more details about the environment that the characters are in or the situation that the characters are going through. Here, we see that Evelyn is in some kind of race, but most of the sentences are generally stating that it was difficult.
In order to support that statement that the climb wouldn't be easy, the author included the sentence "The sound of the rasping breathing of her competitors trailed close behind her". These details indicate that it's a close race, which may be part of the reason why the race and the climb would be difficult.
Hope this helps!