Answer:
Mining affects biodiversity at multiple spatial scales (site, landscape, regional and global) through direct (i.e. mineral extraction) and indirect processes (via industries supporting mining operations, and external stakeholders who gain access to biodiversity-rich areas as the result of mining).
Explanation:
The answer is A. Tú tocas el piano. Because Tu tocas is the only correct way of saying you are playing the piano in this instance. C is saying "tocan" which is wrong because it's saying you but then using a the group form of playing. The same thing with B, it's also using the group form of playing and it's past tense. And D is using the I form of playing not the you form.
B is correct : Usted es trabajador.