Q: Fact 1: Changes in the pH of soil can cause plants to die. Fact 2: Famines are extreme shortages of food that cause people to die of starvation. Given the two facts above, changes in what can cause extreme shortages of food?

Options are:
- pH of soil
- Dehydration
- climate
- colder weather
- global warming
- salinity
- Time and energy
- Winter
The answer is:
pH of soil