1. I believe the correct answer is: “A trip to the ocean can be a relaxing escape from the everyday pressures of life.”
Topic sentence is the sentence that summarizes the main idea of a paragraph, which is in this case a relaxing escape from pressure. The topic sentence is usually at the beginning of the paragraph (first sentence, or first and second), but can be found anywhere in the text.
2. I believe the correct answer is: “You should always be careful to avoid overexposure to the sun at the beach.”
In this paragraph the emphasis is on the escape from the pressure and stress of the everyday life, with given examples and explanation of how and why does relaxing on ocean helps. According to that, the last sentence can be easily eliminated, as it is advice of how to take care of your skin in the sun, not on how to relax.