human
Considering the provided database schema and associated query, produce SQL code to retrieve the answer to the query. 
###Database Schema: Model, Years, Engine code, Power, Torque
###Question: What is the torque of the xdrive20d model, which has a power of ps (kw; hp)@4000?
gpt
SELECT Torque FROM table WHERE Power = ps (kw; hp)@4000 AND Model = xdrive20d