Freezing causes a solid to form, and lower temperature thresholds are at freezing. Given these facts, what causes a solid to form among the following options:
- sunlight
 - evaporative cooling
 - gases
 - Physical weathering
 - water evaporation
 - lower temperature thresholds
 - exposure to cold
 - fissures of hot, acidic water


 

      lower temperature thresholds   