Final answer:
Marla's description as being desperate for an afternoon nap indicates that she has a strong desire or need for rest, which means she greatly desires to take an afternoon nap.
Step-by-step explanation:
If Marla can correctly be described as desperate for an afternoon nap, it must be true that she greatly desires to take an afternoon nap. Being desperate for something means having a strong need or desire for it. Therefore, the correct answer to the question is c. She greatly desires to take an afternoon nap. This implies Marla is likely experiencing physical or mental exhaustion and is intensely in need of rest to rejuvenate.