Which of the Following Statements About GDP Is Correct

Which of the following statements about GDP is correct?

A) Nominal GDP values production at current prices,whereas real GDP values production at constant prices.
B) Nominal GDP values production at constant prices,whereas real GDP values production at current prices.
C) Nominal GDP values production at market prices,whereas real GDP values production at the cost of the resources used in the production process.
D) Nominal GDP values production at the cost of the resources used in the production process,whereas real GDP values production at market prices.