What is the surface area of the soild?

The specific surface area of soil and soil constituents can range from less than 0.1 m 2 g −1 (1 × 10 2 m 2 kg −1 ) for coarse sands to more than 800 m 2 g −1 (8 × 10 5 m 2 kg −1 ) for expandable clay minerals such as montmorillonite

i think the answer is d im not sure