What statement best filling in the first blank of this proof and completes the sentence: "It is given that..."
A. mZA=mZB
B. of the definition of right angles
C. LA and ZB are right angles
D. m2 A = 90° and m2 B =90

There are three bags: a (contains 2 white and 4 red balls), b (8 white, 4 red) and c (1 white 3 red). you select one ball at random from each bag, observe that exactly two are white, but forget which ball came from which bag. what is the probability that you selected a white ball from bag a?