SAT Question c943acba: Probability And Conditional Probability answer and explanation with Desmos solution

Choice B is correct. If a house from the street is selected at random, the probability of selecting a house that is blue is equal to the number of houses on the street that are blue divided by the total number of houses on the street. Since there are $2$ blue houses on a street with $7$ total houses, the probability of selecting a house that is blue from this street is $\frac{2}{7}$.