The correct answer is After surviving those miserable hours in the desert, I learned the value of being prepared.
Step-by-step explanation:
In general, the conclusion should summarize the information of the text and add any ending ideas. In the case of personal narratives, it is common the author adds a final reflection about the experience described; especially the positive or negative impact this had. In this context, the sentence that should be added to make this conclusion better is "After surviving those miserable hours in the desert, I learned the value of being prepared" because this is the only option that refers back to the experienced described and states a positive aspect or lesson this experienced lead to.