Determine from the following choices which correctly show the equality and conversion factors for nanograms and grams.

• A. 1 g = 1×10³ ng;
  1 g / 1×10³ ng and 1×10³ ng / 1 g
• B. 1 g = 1×10⁶ ng;
  1 g / 1×10⁶ ng and 1×10⁶ ng / 1 g
• C. 1 g = 1×10⁹ ng;
  1 g / 1×10⁹ ng and 1×10⁹ ng / 1 g
• D. 1 g = 1×10¹² ng;
  1 g / 1×10¹² ng and 1×10¹² ng / 1 g

Answer: (C)