Destiny has a bag with 3 green, 4 red, and 5 blue marbles. Destiny will pick 2 marbles from the bag, one at a time without looking. She will not replace a marble before picking the next marble. What is the probability of Destiny picking a red marble, followed by a green marble?

A. 1/12
B. 1/11
C. 7/12
D. 1/2