Changes in the pH of soil can cause plants to die, and famines are extreme shortages of food that cause people to die of starvation. Given these facts, changes in what can cause extreme shortages of food among the following options:
- pH of soil
 - Dehydration
 - climate
 - colder weather
 - global warming
 - salinity
 - Time and energy
 - Winter


 

 pH of soil        