This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to maintain a pale complexion
Apply sunscreen daily.
Sunscreen should be applied every day, regardless of the time of year. Spf 15 or above is recommended.

Available choices: (a). For general skincare, aim for an sunscreen with spf 15 or higher, or even a tinted one. Exposing your skin to the sun can cause acne and unattractive breakouts, among other health problems.. (b). It's an important ingredient in any skin care regimen. Apply a low-spf sunscreen to your face for protection against the sun, and a normal spf 15 sunscreen to cover your face and eyes.. (c). In case you're uncertain as to which type of spf you need, remember that the number of spf helps to determine how long the product will be effective in protecting you before having to reapply it. In other words, it helps you to figure out how long you can stay in the sun without burning.. (d). You should also apply a broad-spectrum sunscreen with uva or uvb protection like spf 15 or higher. If you require more sunscreen, then use a higher spf one day a week..
The answer is:
(c).