You are presented with the question "Changes in what can cause extreme shortages of food?" and the following answer choices: 
- pH of soil
 - Dehydration
 - climate
 - colder weather
 - global warming
 - salinity
 - Time and energy
 - Winter

Now knowing that 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, choose the best answer.


 

 pH of soil        