Question:
Who was the head of Treptow-Köpenick in Aug, 2009?

Context:
 Gabriele Schöttler is the head of the government of Treptow-Köpenick from Oct, 2006 to Oct, 2011. 
 Oliver Igel is the head of the government of Treptow-Köpenick from Oct, 2011 to Dec, 2022. 
 Klaus Ulbricht is the head of the government of Treptow-Köpenick from Jan, 2001 to Oct, 2006.

Answer:
Gabriele Schöttler