SAT Question 4e527894: Probability And Conditional Probability answer and explanation with Desmos solution

Choice B is correct. It's given that there are $20$ buttons in a bag and $8$ of the buttons are white. If one button from the bag is selected at random, the probability of selecting a white button is the number of white buttons in the bag divided by the total number of buttons in the bag. Therefore, if one button from the bag is selected at random, the probability of selecting a white button is $\frac{8}{20}$.