Final answer:
If experiencing symptoms of dehydration, the best immediate action is to drink water or a rehydration solution. Sugary sodas and high-salt snacks should be avoided as they can worsen dehydration.
Step-by-step explanation:
The first thing you should do if you experience any of the symptoms of dehydration is drink water or a rehydration solution (Option C). This is because dehydration occurs when the loss of water exceeds the intake, leading to the body's water content being reduced. To stay hydrated, it is important to consume fluids that help to replenish the body's water levels, preferably without added sugars or high sodium content that can actually worsen dehydration.
Drinking sugary sodas as a response to dehydration symptoms is not advisable, due to the high sugar content with no other nutrients, which can lead to additional health issues. Similarly, consuming high-salt snacks can increase sodium levels, leading to further dehydration. Resting through a long nap does not directly address the imbalance of water in the body. Therefore, Option C is the most appropriate immediate action to take if experiencing signs of dehydration.