What is the cost per ounce? Who is the manufacturer? Is the product waterproof? How much protection does it provide?
I gave my students this multiple choice question: When buying a sunscreen, which is the best question to keep in mind while reading the label for maximum effectiveness?

Only one answer is correct among these 4 choices:
- What is the cost per ounce?
- Who is the manufacturer?
- Is the product waterproof?
- How much protection does it provide?

Could you tell me which one is correct?

How much protection does it provide?