At a game booth, a student gets a box of candy as the prize for winning a game. The boxes come in four colors: white, red, green, and blue. There are 10 boxes of each color. All the boxes are equally likely to be given away as prizes. Which expression shows the probability of the first winner receiving a white box and the second winner also receiving a box of the same color? (1 point) Select one:
a. (10/40) * (9/39)
b. (10/40) * (10/39)
c. (10/40) + (9/39)
d. (10/40) + (10/39)