B. Despite the fact that cars cause pollution, people want them.

Cars cause pollution but people still want them.
-> Despite the fact that cars cause pollution, people want them.
=> B

Cars cause pollution but people still want them.

A. Because cars cause pollution, people want them.

B. Despite the fact that cars cause pollution, people want them.

C. Cars cause pollution although people want them.

D. Cars cause pollution because people still want them.