Fact 1: Ultraviolet light causes sunburn.

Fact 2: Sunburns are painful and can be dangerous.

Given the two facts above, answer the question "what can be painful and dangerous?" with the following options: 
- Brutal temperatures
 - smoking cigarettes
 - Pesticides
 - ultraviolet light
 - weathering
 - hyperthyroidism
 - nutrients
 - oxygen


 

    ultraviolet light     