Answer: Your answer is going to be C)
Here is my explanation, very simple! So if you count all the balls together in answer's A) B) and D) there aren't 3 balls in each, so for example answer A) has 4 red ball's. B) only has 1 red ball, D) also has 1 ball, so C) is your only reasonable answer because although all the containers have a total of 7 ball's there is not enough for your probability. being said your container/answer is C!
