Here's a problem to solve: In the geologic past, abiotic factors such as volcanic eruptions have had an impact on the availability of resources. How can volcanic eruptions impact the availability of resources?

Among the 4 following options, which is the correct answer?

- A: by decreasing the thickness of soil
 
- B: by causing more heavy rains to erode topsoil
 
- C: by disrupting the sunlight from reaching producers
 
- D: by causing the surface of Earth to be warmer than usual
 