Question:
Who was the head of Brandenburg in Apr, 2008?

Context:
 Manfred Stolpe is the head of the government of Brandenburg from Nov, 1990 to Jun, 2002. 
 Matthias Platzeck is the head of the government of Brandenburg from Jun, 2002 to Aug, 2013. 
 Dietmar Woidke is the head of the government of Brandenburg from Aug, 2013 to Dec, 2022.

Answer:
Matthias Platzeck