A wife is about to give birth to a twin. Which of the following illustrates the sample space for the possible sex of the babies?

A. S = { (B , B) , (G , B) }
B. S = { (G , G) , (B , G) }
C. S = { (B , B) , (G , G) , (B , G) }
D. S = { (G , G) , (B , B) , (B , G) , (G , B) }