2010 Audi A6 Quattro Passenger Seat Back Will Not Recline

What is your question?

The passenger seat back on my 2010 Audi A6 stopped reclining. The seat will move in every other direction...up, down, back, forward and even the back on seat can be brought forward. But, the back of the seat will not recline or go back from the position which it is in. Any suggestions?