Final answer:
The author should choose the word 'tore' to illustrate the difficulty and length of the day of hiking for the llamas.
Step-by-step explanation:
In order to illustrate how long and difficult the day of hiking is for the llamas, the author wants to choose a word that emphasizes their speed and determination. The best word to achieve this goal is tore.
This word conveys the sense of rapid movement and intensity, showing how the llamas hurried down the 6.6 mile-long trail with packs full of dirty laundry. It highlights the challenging nature of the hike and the determination of the llamas to complete it quickly.