There are 7 red marbles, 7 blue marbles, 7 yellow marbles, and 7 green marbles in a bag. If a person randomly selects 1 marble from the bag, what is the probability that the person selects a blue marble? (HOW DID YOU GET YOUR ANSWER, PLEASE SHOW ME YOUR WORK!!)
A. 0.75
B. 0.5
C. 0.25
D. 0.0625