"If real GDP stayed the same while nominal GDP declined between 2008 and 2009, then the GDP deflator must also have declined."
A. Disagree. If nominal GDP declined between 2008 and 2009, then the GDP deflator could have gone up.
B. Disagree. If real GDP declined between 2008 and 2009, then the GDP deflator must also have declined.
C. Agree. If nominal GDP declined between 2008 and 2009, then the GDP deflator must also have declined.
D. Disagree. If nominal GDP increased between 2008 and 2009, then the GDP deflator must have remained the same.
Answer: C. Agree. If nominal GDP declined between 2008 and 2009, then the GDP deflator must also have declined.