How does the quantity of zinc used in a mineral-based sunscreen affect an individual's chance of getting a sunburn?


Which statement forms the best testable hypothesis for the question?


1) If spray-based sunscreens require less time to apply and dry because they include less zinc, then individuals who use spray-based sunscreens will have a reduced chance of getting a sunburn.

2)If the quantity of zinc in a mineral-based sunscreen affects the total amount of UVA and UVB rays absorbed, then increasing the amount of zinc will decrease an individual's chance of getting a sunburn.

3)if mineral-based sunscreens are thick and opaque when applied due to more zinc, then they will decrease an individual's chance of getting a sunburn.

4)if mineral-based sunscreens contain more zinc in them, then individuals who use them will decrease their chances of getting a sunburn.