Answer:
D.
Step-by-step explanation:
Blue beads are 3 times more likely to be pulled. Therefore, since there are 12 beads in total the ratio which would fit the ratio of probability to pull blue beads compared to black beads would be 9/12 leaving 3/12 probability to pull a black bead. if you simplify the fractions you get 3/4 and 1/4 where 1/4 (the probability to pull a black bead) is three times less than the probability to pull a blue bead.