a decrease in the rate of soil erosion a decrease in the fertility of the topsoil an increase in the production of plants used for medicines an increase in the amount of oxygen produced in the atmosphere
I gave my students this multiple choice question: As a result of rain forest deforestation, some organisms lose their habitats. Which is also an effect of rain forest deforestation?

Only one answer is correct among these 4 choices:
- a decrease in the rate of soil erosion
- a decrease in the fertility of the topsoil
- an increase in the production of plants used for medicines
- an increase in the amount of oxygen produced in the atmosphere

Could you tell me which one is correct?

a decrease in the fertility of the topsoil