Explanation:

- Deforestation leads to soil erosion: Without tree roots to hold the soil together, the ground becomes loose and is easily washed or blown away.

- Deforestation results in biodiversity loss: Trees provide habitats and food for countless species, and their removal threatens plants, animals, and insects alike.

- Option 1, Soil erosion: True as a consequence of deforestation.

- Option 2, Biodiversity loss: True as a consequence of deforestation.

- Option 3, Both (a) and (b): This is the correct option since both consequences are true.

- Option 4, None of the above: Incorrect, as both consequences are relevant.