Answer: Working as a waitress taught me some valuable skills.
Explanation: The sentence above provides a good foundation for a writer to write a paragraph about as it gives a basis to write upon (the valuable skills that were taught.)
The first sentence provided would be far less desirable as it fails to maintain an academic tone and states too directly what is going to be written about.
The second sentence could also be used as a topic sentence, but without a specific area of "world hunger" being used the paragraph could be about anything. All that is given is that the paragraph will be about "something."
